Charities that work with children, as well as disabled and elderly people, are increasingly subjecting volunteers to criminal background checks, reports USA Today.

Checks by nonprofit groups for convictions on drug, domestic-violence, child-abuse, or sex-crime charges have risen steadily since enactment of the National Child Protection Act in 1993. The measure was amended five years later to enable charities and businesses to use national fingerprint databases to screen volunteers.

Several states have followed suit, with Minnesota last year making such checks mandatory for organizations that work with vulnerable clients.