Some evidence suggests that expertise and observational skills training can reduce attentional errors, such as change blindness. Laypeople typically assume that law enforcement officers possess acute observational skills, but no research to date has compared law enforcement and lay samples on their susceptibility to change blindness. In the present study, student and law enforcement samples completed a change blindness task and attempted to identify the target(s) from four line-ups. Law enforcement officers and students were equally susceptible to change blindness regarding the switch in the target's identity, but students were more likely than officers to detect changes in the target's clothing. Students also performed better on the line-up task, overall, than officers. Additionally, whereas students' confidence was positively correlated with identification accuracy under some circumstances, officers' confidence was either uncorrelated or negatively correlated with accuracy. We discuss the implications of these findings and suggest some factors accounting for law enforcement officers' relatively poor performance on these tasks.