This article examines the effect that collective bargaining had on official crime statistics compiled between 1998 and 2009 in Montreal, Canada. Police officers collectively decided to reduce their use of record-discretion on two occasions, to increase administrative workload and pressure their employers. Considerable increases of recorded assaults and mischief were observed, despite no apparent variation of reported infractions measured by calls for service. Recorded and reported car thefts and burglaries displayed no significant variation. Results suggest that observed variations can be explained in terms of temporary differential treatment of specific incidents rather than increases of reported criminality or proactive police activity. This research challenges the reliability of official statistics as measures of crime and demonstrates that external circumstances can influence police recording practices.