B-events are matters which are better known to listeners than to speakers. This paper studies the detectives’ use of B-event statements in two different environments in their interactions with suspects/witnesses. The first type of environment are relatively co-operative sequences during which the aim is the reconstruction of events and constructing the record; here, B-event statements are realised as confirmation seeking questions. The second type of environment, a hostile interactional environment, is composed of argumentative sequences in which detectives aim to determine who are the perpetrators of crimes; in these sequences, the detectives’ B-event statements are realised as accusations. While performing the two activities, the detectives signal different epistemic levels and stances at the turn level. Thus, the former B-event statements are mostly epistemically downgraded, while the latter are mostly upgraded, in order to facilitate undertaking these different activities during police questioning.