refers to the previous or past criminal involvements and records, convictions and acquittals of the defendant in criminal cases. It is a slang for the same. The previous verdicts on the same person/defendant is of importance to derive the nature of person he /she is.
Found on http://www.legal-explanations.com/definitions/prior.htm
n. slang for a criminal defendant's previous record of criminal charges, convictions, or other judicial disposal of criminal cases (such as probation, dismissal or acquittal). Only previous felony convictions can be introduced into evidence. However, the record of "priors" can have an impact on sentencing, as with prior drunk driving convictions re
Found on http://dictionary.law.com/Default.xhtml?selected=1604
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