DS Luke Crisp is a police officer who is first introduced when Heather Trott was murdered in March 2012. DS Crisp returned to the show when Ben Mitchell confessed to murdering Heather Trott. A police detective and a member of the homicide assessment team, Crisp was investigating the murder of Heather Trott. He questions Phil Mitchell, Jay Mitchell, Billy Mitchell, Ben Mitchell and Shirley Carter about the incident and later concludes that the supposed burglary in her flat was faked.