Police respond to a variety of situations on a daily basis. A major component of their work is to collect evidence from witnesses (and other sources) to make decisions about whether further investigation is warranted or if an immediate charge should be laid. While it is well established that the use of open-ended questions is the best way to elicit verbal evidence from people, it is not known the extent to which an interview would be comprised of open-ended questions (versus other types) across different situations. In the present study we examined the impact of offence type on police officers’ (N = 55) use of open-ended questions at various levels of skill acquisition (i.e., stages of training) under controlled conditions. Results showed that offence type does impact adherence to open-ended questioning and open-ended question usage increased as a result of training. Some offence types, even at the conclusion of training, were more amenable to the use of open-ended questions compared to others. The findings have implications for researchers who evaluate the efficacy of training programs, individuals who design interview training, and organisations who might assess trainees on their open-ended question usage at various training intervals.