As the saying goes, "when it comes to human beings, the best predictor of future behavior is past behavior." But can pop psychology mantras be maxims of law in criminal courts? Can evidence of past crimes, even far off or juvenile offenses, be used against you in a new case?
It's a broad question, and one that can only be answered with a few specifics, additional circumstances, and, of course, some caveats. Here's what you need to know.
Police and prosecutors will generally have access to all of your criminal records. Even if you've had them expunged, law enforcement can see if you have past convictions, and those past convictions can affect what kind of charges will be filed against you and the kind of plea bargain prosecutors may offer in your case. Often, a second or third offense (of the same crime) can be charged as a felony, meaning increased penalties or prison time, and prosecutors are far less inclined to be lenient with a repeat offender.
Additionally, if the past conviction included probation or parole, a new arrest or criminal charges could violate the conditions of your release, possibly sending you to jail. And if you remain subject to a suspended sentence or deferred prosecution, those prior charges could be reinstated.
As general rule, the law leans in the opposite way of psychologists when it comes to predictive behavior, and past criminal behavior cannot be used to prove that you committed a crime. Even if you've been convicted of a DUI, prosecutors can't use that to say you drove drunk again.
But there may be exceptions if you choose to testify on your own behalf. While you are not legally required to do so, if you choose to take the stand, your credibility as a witness will be an issue. This may open the door for prosecutors to ask about past convictions, provided they will shed light on your reliability as a witness or propensity to tell the truth. Even then, there are a variety of factors that will determine whether the past convictions will be relevant, or admissible as evidence.
The best way to know whether and how your past crimes may come back to haunt you is to contact an experienced criminal defense attorney.