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

Law Enforcement Testimony

Potential Pitfalls for Police Witnesses

Although police officers and other professionals peripherally involved with the criminal justice system should be by nature more cooperative and competent than civilian witnesses, it is wise to leave nothing to chance. Some frequently encountered pitfalls include: a) relying too much on notes and reports; b) arguing with defense counsel; c) appearing to be too invested in obtaining a conviction; d) offering unsolicited and improper conclusions and opinion testimony; e) being non-responsive to the point of adding gratuitous comments; f) using too much law enforcement jargon; g) being overly defensive when in error; h) relying too much on “we” type testimony instead of telling what they themselves did, or testifying to what they “usually” do as opposed to what they actually did in this case.

REMEMBER: In many impaired-driving cases, you will have a pretty solid suspicion that the defendant is impaired, and less safe to drive, within a matter of moments after your initial contact. Almost everyone has encountered the “falling down drunk” at least once; it doesn’t take special skill to recognize it. However, it takes skill to paint a detailed word picture of the officer’s observations, whether the defendant was falling down drunk or less so, to explain to the jury/judge that the sober individual sitting in the courtroom today was not in that condition on the date/time/location in question. The ability to convey this information in a manner understandable to the jury is what makes the officer an “expert” witness even if not within the legal meaning of “expert witness.”