Banner for The Criminal Justice Systems: A Guide for Law Enforcement Officers and Expert Witnesses in Impaired Driving Cases

Glossary of Terms

Accusatory Instrument A legal document that accuses a defendant of one or more crimes. There are various types of accusatory instruments, including traffic tickets, complaints, informations, indictments, and superior court informations.

Acquittal A decision by the trier-of-fact (the judge if a non-jury trial, otherwise the jury) that there was not enough evidence beyond a reasonable doubt to decide that the defendant committed the crime(s) with which he or she was charged. It is not a finding of “innocence” although it could mean that the jury thinks the defendant did not commit the crime. On the other hand, an acquittal could mean the jury had some belief that defendant committed the crime, but it also had some doubts. For example, in an impaired-driving case, the jury may believe the defendant was driving the car, crossed the center line three times in less than a minute, and had some amount of alcohol in the hours before he or she drove. They might even believe that the driver was more tired than he or she should have been in order to drive with the highest degree of safety. However, the jury might have some doubts as to the prosecution’s evidence that the defendant had five 12 ounce-beers in the hour leading up to the time defendant was stopped, and instead think maybe it was only two beers, as the defendant himself told the officer on the scene. Thus, the jury could conclude that while the driver might have had twelve beers, he might only have had two, and because they had reasonable doubt as to how much beer was consumed, they voted to acquit.

Appeal A review by a higher court of the correctness of legal proceedings in a lower court. Particulars of the legal proceedings may vary not only from State to State, but also between jurisdictions (the geographic region over which a particular criminal justice system—law enforcement, prosecutors, the courts, probation/parole—has authority) within a State. Generally speaking, petit trial level courts (town/city courts, district courts) conduct hearings and other legal proceedings for lesser offenses. The right to a jury trial at this level may or may not exist, depending upon an individual State’s laws. Criminal or superior courts (sometimes called “circuit courts”) conduct hearings, proceedings, and jury trials in the more serious cases known as “felonies.” They generally have the right to review proceedings which have taken place in the lower court. Appellate courts review the trial proceedings of the felony criminal courts for the correctness of legal issues.

It is at trial that the prosecutor will offer evidence of guilt against the defendant in an effort to prove the defendant guilty beyond a reasonable doubt. If found guilty, the defendant will oftentimes appeal to a higher court, made up of one or more judges, to argue that errors of law occurred during the trial (e.g., the judge allowed evidence to be heard that should have been excluded because the police did not follow proper procedures in collecting it) and thus the guilty verdict should be overturned (thrown out).

Arraignment The initial appearance of the defendant in court to answer the charges in an accusatory instrument. At the arraignment, the judge (1) provides the defendant with a copy of the accusatory instrument, (2) advises the defendant of the right to counsel and arranges for counsel to be provided without cost if the defendant is indigent, and (3) considers the matter of bail.

In the typical felony prosecution, the defendant will first be arraigned in a local criminal court, then, after the case moves to a superior court through a grand jury indictment or a waiver of indictment, the defendant will be arraigned in the superior court. Again, the specifics will vary between States.

Arrest Taking a suspect into custody for the purpose of prosecution on a criminal charge. To be legal, an arrest must be based on probable cause—a belief that it is more likely than not that the suspect has committed an offense.  

An arrest may be made with or without an arrest warrant. In general, an arrest warrant is not necessary if the police officer can take the suspect into custody in a public place. If the suspect is in a private place such as a residence, the officer generally cannot enter the residence to make the arrest unless there is an arrest warrant reciting the residence as the suspect’s address, or the officer obtains a search warrant for the residence, or someone in the residence voluntarily allows the police to enter. There are exceptions to this “do not enter” rule which are beyond the scope of this document.

Arrest Warrant A judge’s written authorization to take an identified suspect into custody. To obtain an arrest warrant, a police officer must file papers with the court providing probable cause to believe that the individual has committed a crime.

An impartial judge will review the evidence and determine if it is more likely than not that the defendant committed the acts (“probable cause”). Once the warrant is signed by the judge, if the suspect cannot be found, an arrest warrant may be entered in the national computer system to alert the wanting agency if the suspect is stopped by another agency. One disadvantage to the police in getting an arrest warrant is that the filing of the papers with the court may trigger the suspect’s right to counsel, so there can be no questioning of the suspect after arrest, unless an attorney is actually present and allows the suspect to be questioned.  However, the “no questioning” rule is not a bar to using statements voluntarily made by the defendant. A defendant who starts chatting while sitting in the back of the patrol car—“I was driving, but you’ll never prove I was drunk”—is in custody, but not being questioned and thus does not have a right to have his statements excluded at trial.

Bail A down payment of money to assure that the defendant will return to court when required. At the arraignment, the court will determine if bail is required, and if so will fix the amount and will order the defendant held in jail until bail can be posted, generally in the form of cash or a secured bond. If bail is posted, the defendant is released from jail and is allowed to remain at liberty pending the outcome of the prosecution. If the defendant fails to return to court, the bail is forfeited (turned over) to the State; if the defendant appears in court as required, the bail is returned to the party who posted it.

Instead of setting bail, the court may elect to order a defendant “released on recognizance,” meaning the defendant is trusted to come back to court when required, without any bail being set. This is common for lower level offenses committed by persons who live and/or work in the community.

Bill of Rights The first ten amendments to the United States Constitution. The Bill of Rights includes numerous rights specifically intended to benefit defendants in criminal prosecutions. Because the Constitution is the supreme law of the United States, no Federal, State, or local law can diminish those rights.

The Bill of Rights sets forth rights, but is silent concerning remedies for the violations of those rights. The United States Supreme Court has filled the gap by fashioning remedies through case law, including the remedy known as the exclusionary rule (discussed below).

Booking The process of officially recording an arrest. It typically includes (1) photographing the defendant (i.e., taking a “mug shot”); (2) fingerprinting the defendant; and (3) obtaining pedigree information (name, address, date of birth, etc.) from the defendant. Many lower level offenses (e.g., speeding tickets) do not require booking, and in those cases the defendant is simply issued a ticket to appear in court on a future date.

In some States, if an arrest ultimately results in a dismissal of the charges, or if the conviction is for an offense below the level of a crime, or if the defendant is under a certain age as determined by individual State law, the arrest records generated through the booking will be sealed, so the arrest will not result in a criminal record.

Count One Charge within an accusatory instrument. A single criminal incident commonly gives rise to multiple charges. For example, a defendant breaks into a home and steals the flat-panel TV, several gold bracelets, and three diamond rings. During the course of gathering up these items, he is confronted by the homeowner and punches her in the face. In addition to the burglary charge, additional charges might include damage to property (breaking the window to gain entry), theft of property, and assault/battery for hitting the homeowner.

Daubert Hearing A pretrial hearing used in some jurisdictions to determine whether or not “scientific evidence” will be allowed at trial. Under this test, judges evaluate whether the evidence is both “relevant” and “reliable” in determining if it will be admissible at trial. This standard differs from Frye in that it does not mandate a showing that the evidence has been “generally accepted in the scientific community.”

Deposition Witness testimony taken under oath in response to written interrogatories (a list of questions prepared in advance) or oral questions during the investigation or pretrial phase of a legal action. 

Discovery A pretrial stage where the parties exchange information about the evidence and arguments they will offer at trial. In many States, the burden of supplying discovery information rests almost entirely upon the prosecution. This is because the presumption of innocence and the privilege against self-incrimination generally permit a defendant to remain silent throughout the prosecution.

One of the discovery items that the prosecution may be asked to supply is a “bill of particulars,” which is a brief statement of the core facts of the case. A copy of the bill of particulars is filed with the court and is open to public inspection. Other discovery items, such as police reports and lab reports, are generally not filed with the court and simply pass between the attorneys.

Exclusionary Rule Simply stated, the exclusionary rule provides that evidence obtained through unconstitutional acts of law enforcement officers cannot be used to prove the defendant’s guilt at trial. If the court determines, usually at a pre-trial hearing, that crucial evidence was gathered by law enforcement in an unconstitutional manner, the charges may be dismissed even though the evidence is reliable and, if it could be used, would prove that the defendant is guilty.

The rationale for the exclusionary rule is deterrence. The idea is that if law enforcement officers know that unconstitutional conduct will result in exclusion of evidence, they will not act unconstitutionally. Evidence that is excluded from the trial by application of the exclusionary rule is said to be suppressed.

Felony A crime generally punishable by more than one year in prison. However, a sentence may include no jail or prison time, depending upon the degree (“seriousness”) of the charge and the defendant’s prior criminal history, if any.

Frisk A quick search of an individual’s external clothing to determine whether the individual is armed with any sort of dangerous implement—a gun, knife, box cutter, screwdriver, etc. A frisk is also known as a “pat down.” Generally, a frisk is legal if the officer has reasonable suspicion to believe that the individual might be dangerous. The officer will need to articulate the basis for this belief in order for any evidence discovered as the result of the frisk to be admitted in subsequent criminal proceedings.

Frye Hearing A pretrial hearing used in some jurisdictions wherein the court determines if the “scientific evidence” is “new or novel” and if so, whether the principle or technique has been “generally accepted” in the relevant scientific community. If not new or novel, the evidence may be admitted. If new or novel and not yet accepted by the relevant scientific community, the evidence will not be admitted at trial.

Grand Jury A jury that determine if there is adequate evidence to charge a defendant with a crime. Not all States use the grand jury system. Of those that do, some may require first-hand testimony from witnesses, including expert witnesses. Other States allow one person, such as an investigator employed by the prosecutor’s office, to summarize the details of the case without the need of separate testimony from individual witnesses.

The following table contrasts a typical grand jury with a trial jury (again, some specifics, such as the number of jurors, will vary from State to State):


Grand Jury

Trial Jury

What is determined?

whether to charge

whether to convict

Prosecution’s burden of proof

probable cause

proof beyond a reasonable doubt

Number of jurors



Number of jurors who must be present to conduct business

16 of 23


Number of jurors the prosecution must convince



Product of a convinced jury


guilty verdict

Persons present

        jurors, witness prosecutor, stenographer, defendant may be present, but only at a particularly designated time and with counsel of his choice

       jurors, witness, prosecutor, stenographer defendant, defense attorney, judge, court clerk , court attendants, spectators

Public access

closed to the public

open to the public

Incarceration The all-encompassing term for various forms of court-ordered confinement. There are several forms of incarceration that may be imposed upon defendants depending on the crimes they have committed. Local jails hold defendants who are not yet convicted but are being held in jail in lieu of bail, and also hold defendants who have been convicted and sentenced to terms of incarceration of one year or less. A State prison system holds inmates who are convicted of felonies and sentenced to terms of incarceration in excess of one year.

Indictment The accusatory instrument issued by a grand jury. It contains one or more charges against the defendant. Each charge is referred to as a count of the indictment.

Local Criminal Court (“district court”) A city, town, or village court.

Misdemeanor A crime generally punishable by a maximum of up to one year in local jail.

Mistrial A judge may declare a mistrial—end the trial—for a number of reasons, including improperly admitted evidence (e.g., testifying about statements made by the defendant which were previously ruled inadmissible), misconduct by a juror (e.g., discussing the case outside of the courtroom), or a hung jury (jury cannot reach a verdict during its deliberations due to lack of agreement). A mistrial generally means a retrial on the same subject.

Motion in Limine A request to the court, made before the start of a trial, asking the judge to make a decision on a legal matter. The judge’s decision will impact how the case proceeds. Motions made by defense counsel could include Motion to Exclude Evidence (e.g., based on lack of reasonable suspicion for the stop and/or probable cause for arrest). The prosecution might request a court order for the production of the defendant’s substance abuse treatment records.

Order A direction by a judge that something be done or not be done. For example, a judge may order evidence suppressed, which means the prosecution may not offer the evidence at trial. Or a judge may issue an “order of protection” commanding a defendant to have no contact with a victim.

Parole Supervision by a State parole officer of an inmate after his or her release from State prison. Contrast probation, which is supervision at the local level by a county probation officer (see probation, below).

Post-Conviction and Post-Judgment Motions Used to attack guilty findings. As part of these motions, the defendant may seek an evidentiary hearing to bring to lightfacts not litigated during the trial. For example, a defendant who is challenging the competence of his attorney may bring a post-judgment motion and request an evidentiary hearing to bring to light matters that transpired between attorney and client.

Preliminary Hearing (Felony Hearing) Generally speaking, a defendant who is arrested on a felony charge and held in jail has the right to an impartial testing of the evidence within a certain time frame after arrest. One way to test the evidence is to present the case to the grand jury. In States that do not use the grand jury system, and in rural areas where grand juries sit less frequently, it is more common to test the evidence at a preliminary hearing.

Defendants sometimes agree to waive their right to a preliminary hearing, for a variety of reasons, including a desire to avoid a public airing of the evidence or an agreement with the prosecution to waive the hearing in exchange for disclosure of information about the prosecution’s case.

For lower level felonies, it is very common for defendants to be released on their own recognizance at arraignment, or to have posted bail by the time of the preliminary hearing. This removes the reason for holding the hearing—to test the evidence justifying detention—and so no hearing is held.

Pre-Trial Motions and Hearings A motion is a request by which a party (prosecution or defense) asks a judge to issue an order. For example, in criminal cases, pre-trial motions by defendants commonly include motions for dismissal of the indictment and for suppression of evidence.

Motions that are contested result in hearings. A hearing may simply be an argument by attorneys of legal issues, or it may be an evidentiary hearing at which witnesses testify. The most common pre-trial evidentiary hearing is a suppression hearing where the prosecution calls one or more police officers to testify about the manner in which evidence was obtained. If the prosecution fails to establish that the evidence was obtained in a manner consistent with the defendant’s constitutional rights, the evidence will be suppressed.

Probable Cause (Reasonable Cause) A level of proof that is reached if a reasonable person would conclude that something is probably true. Probable cause is a higher level of proof than “reasonable suspicion,” but a lesser level of proof than “proof beyond a reasonable doubt.” (See each defined, below.)

The probable cause standard is referenced in the Fourth Amendment, and is a required hurdle at several stages of a prosecution. For example, a police officer may arrest a suspect only if the officer has probable cause to believe the suspect has committed a crime. Similarly, a grand jury may indict a defendant only if it finds probable cause to believe the defendant committed one or more crimes.

Some State statutes, such as in New York, commonly use the term “reasonable cause.” That term is synonymous with probable cause and should not be confused with reasonable suspicion, which is a lesser level of suspicion.

Probation A sentence that entails supervision by a probation officer. Probation is possible in cases where the defendant is convicted of a crime that does not mandate incarceration in State prison. Accordingly, probation is a common sentence for defendants convicted of misdemeanors and lower level felonies with little or no criminal history.

It is possible to receive a sentence consisting of both local jail time plus probation. This is often referred to as a “split sentence.” For example, a New York defendant convicted of a certain felonies may be sentenced to six months in jail plus a concurrent term of five years in probation. That means the defendant would first do his jail time and then, when released from jail, would be under the supervision of the probation department until the probation expired.

Probation is often confused with parole, which is supervision by a parole officer following an inmate’s release from a State prison.

Proof Beyond a Reasonable Doubt A level of proof that is reached if a reasonable person would be firmly convinced that something is true. This is a higher level of proof than probable cause. A jury may not convict a defendant unless the jurors are convinced of guilt by proof beyond a reasonable doubt. The law does not require the prosecution to prove a defendant guilty beyond all possible doubt. On the other hand, a reasonable doubt is an honest doubt of the defendant's guilt for which a reason exists based upon the nature and quality of the evidence. It is an actual doubt, not an imaginary doubt.

Reasonable Suspicion A level of proof that is reached if a reasonable person would conclude that illegal activity is afoot. This is a lower level of proof than probable cause. A police officer may not stop an individual unless the officer has a reasonable suspicion of illegal activity, and a police officer may not frisk an individual unless the officer has a reasonable suspicion that the individual may be dangerous to the officer or to others.

Release on Recognizance An order of the court allowing a defendant to be released without bail pending the outcome of the prosecution.

Sealing of Records If an arrest ultimately results in a dismissal of the charges, or if there is a conviction for an offense below the level of a crime, or if the defendant is under a certain age (which may vary from State to State, and also depends upon the level of the offense) the records of the case might be sealed, meaning the arrest would not result in a criminal record.

Generally speaking, sealed records are not accessible to the public, and are not accessible to the police or prosecutors except upon court order. There are some variations to this rule which go beyond the intent of this publication.

Search and Seizure The area of law dealing with the Fourth Amendment’s guarantee that individuals shall be free from “unreasonable searches and seizures.” A search or seizure occurs whenever the police invade an individual’s reasonable expectation of privacy. Stops, frisks, and arrests are examples of police activity that constitute searches and seizures. Any police officer who conducts a search or seizure may be called on to justify his actions in court at a pre-trial hearing, and if he cannot, any evidence obtained through the search or seizure may be suppressed through application of the exclusionary rule.

Search Warrant A written order by a judge authorizing the police to search in a particular place for particular items. A search warrant is valid only if, before issuing the warrant, the judge is presented with facts establishing probable cause to believe the items to be seized will be found in the place to be searched. Typically, the application for the search warrant will consist of one or more sworn statements from knowledgeable persons.

Sentencing The imposition of punishment by the judge following a conviction. The range of possible sentences depends on the level of the offense committed. The most serious crimes (e.g., murder, forcible rape, and armed robbery) require sentences of incarceration in State prison. For lesser crimes, alternatives to incarceration (e.g., probation, community service, and fine) are usually permissible. Sentences may also include provisions for the benefit of the victim, including orders to pay restitution to the victim to defray monetary losses and orders of protection to keep the defendant from contacting or harassing the victim.

An “intermittent sentence” is another form of local jail sentence of one year or less, but instead of being continuously incarcerated, the defendant is in and out during the term of the sentence. This is sometimes called being sentenced to “weekends” because most commonly judges will order defendants to be in jail from Friday evening till Sunday night or Monday morning during the term of the sentence. This is most commonly used when the judge believes the defendant deserves punishment, but wants to allow the defendant to continue to work at his or her job.

An “indeterminate sentence” is a State prison sentence with two numbers defining the term in years, a minimum and a maximum. The sentence is indeterminate in the sense that the parole board, not the judge, determines the defendant’s release date. Examples of indeterminate sentences are sentences of 1 to 3 years, or 2 to 4 years, or 15 years to life.  

Finally, a “determinate sentence” or “fixed sentence” is a State prison sentence having a single number of years. Examples are: 1.5 years, 6 years, or 15 years. The sentence is “determinate” in that no parole board is involved in making the release decision. 

The term imposed by the sentencing judge can be misleading because in many States, as an inducement to good behavior while incarcerated, defendants can earn the right to be released earlier than their stated terms. These inducements include good time, merit time, conditional release, parole release, and other things.

If there are multiple sentences of imprisonment imposed upon a defendant, the sentences will run either “concurrently” or “consecutively.” “Concurrently” means that all the sentences run at the same time and all are satisfied when the longest one is done. “Consecutively” means the sentences are served one at a time, so the sum of the terms is what governs. To make matters even more confusing, some of the sentences may be imposed to run concurrently to each other but consecutively to others. Depending on the circumstances, the choice of concurrent or consecutive may be dictated by statute, or may be left to the judge’s discretion.

Stop Temporary detention of an individual for investigation. To be legal, a stop must be based on reasonable suspicion to believe the individual has committed, or is about to commit, some violation of the law. If the stop yields information to confirm the suspicion, the stop may escalate into an arrest.

For example, upon seeing a car weaving back and forth over the center line, an officer would have reasonable suspicion to believe the driver might be intoxicated. The officer could then stop the car, talk to the driver, and administer field sobriety tests. If that investigation confirms that the driver is intoxicated, the officer would then have probable cause to believe the driver was intoxicated and could lawfully arrest the driver for the crime of Driving While Intoxicated.

Suppression of Evidence A court ruling disallowing evidence due to unconstitutional conduct by law enforcement officers. Suppression of evidence means the court has invoked the exclusionary rule. Evidence may be reliable, yet still be suppressed because it was obtained in an illegal manner.

The evidence sought to be suppressed is usually either (1) an incriminating statement made to a police officer, (2) physical items of evidence seized by the police, such as drugs or a gun, or (3) identification evidence such as lineup identification or an on-the-street show up identification.

Suspended Sentence A sentence in which the defendant could serve a maximum term of say, 10 years, but is allowed to serve far less time in jail in exchange for the opportunity to not engage in any further criminal conduct. If the defendant fails to abide by the directives of his release, his “suspended” sentence is reactivated, and he could serve the entire 10 years.

Trial A trial determines the question of the defendant’s guilt. The verdict of the jury is either “guilty” or “not guilty” on each charge given to the jury for determination. The jury is instructed to find a defendant not guilty if the prosecution fails to prove the charge beyond a reasonable doubt. A verdict of not guilty is not a finding of innocence; rather, it is a finding that the charge is not proven beyond a reasonable doubt.

Generally, the stages of a trial are:

  • Jury selection
  • Preliminary legal instructions by the court to the jury
  • Opening statement by the prosecutor
  • Opening statement by defense counsel
  • Presentation of prosecution evidence
  • Presentation of defense evidence (optional)
  • Presentation of prosecution rebuttal evidence (optional)
  • Summations by defense counsel and prosecutor
  • Legal instructions by the judge to the jury (“the charge” to the jury)
  • Jury deliberations
  • Verdict

In stage 3—the opening statement by the prosecutor—the prosecutor must set forth an outline of the evidence to be presented. This is a very good time for a spectator to hear a summary of the evidence, which may never have been stated in public before.

Warrant A written order by a judge authorizing the police to take some action. An arrest warrant authorizes the police to arrest someone, and a search warrant authorizes the police to search somewhere for something. The Fourth Amendment states that warrants may only be issued upon probable cause (also referred to as “reasonable cause”).