Police overestimation of criminal career homogeneity

Police presumptions about criminal career trajectories have been little studied. The exploratory
study reported here involved 42 police staff of varying rank and experience. Participants were
asked to complete a questionnaire which asked them to predict the type of offence that an
individual with specified prior record was most likely to commit next. Participating police
personnel substantially overstated the homogeneity of criminal careers, i.e. the nature of prior
offences determined their prediction of their next offence more than available official data would
deem reasonable. An incidental finding was that officers who rated the probability of further
offending highest were also those who thought criminal careers most specialised. Theimplications
for operational police decision making are discussed and held to be profound.