Burglar alarms have been protecting residences and buildings for over 150 years. For most of this time, their utility in reducing the incidence of burglary has been based on anecdotal and intuitive notions. In recent decades researchers have established qualitative bases for the utility of residential alarms in the reduction of incidents in the United States. Camera systems have arrived more recently as anti-burglary protective measures. This study examines perceptions on the deterrence impact of alarms and other burglary-deterrent measures from 242 convicted burglars serving time in four Ohio prisons. The findings show that evidence of a residential burglar alarm, outdoor cameras, or surveillance equipment are powerful deterrent factors in the decision process of most actors.