Roseanna is a 1993 Swedish police film about Martin Beck, directed by Daniel Alfredson, based on the novel Roseanna (1965).
A young American tourist is murdered while on board a cruise ship set sail for Sweden. The body of a victim is discovered in the water by the police, who can't determine the cause of death due to loss of clues. When they finally find something, they use a policewoman as live bait to catch a killer, where she almost gets killed.