In the novel Sleeping Murder, Detective Inspector Primer is a police officer from the headquarters of the county where Dillmouth is situated. He takes over the investigative lead from Inspector Last when it becomes clear that the murder of Lily Kimble had ramifications which could include events from long ago such as the disappearance of Helen Halliday. Primer knew Miss Marple or at least knew of him because his Chief Constable Colonel Melrose had once pointed her out out to him.
BBC's Miss Marple
ITV's Agatha Christie's Marple
In the ITV 2006 adaptation of the novel, the character becomes "Chief Inspector Arthur Primer" and is portrayed by Russ Abbott. Here Inspector Last is not featured and Primer has a much larger role than in the original novel. He investigated the death of Kelvin Halliday in 1934 and concluded that it was an open and shut case of suicide. Speaking to Miss Marple about those events some 18 years later, he remarked that there nothing untoward or unusual except that Mrs Fane had reported an Indian man at the Dillmouth promenade during the night Helen disappeared. He was not keen for Miss Marple to resurrect the case in the 1950s as he would be retiring shortly but she nonetheless convinced him to come with her to interview Dr Kennedy. Shortly thereafter, his retirement plans are postponed as he has to deal with the murder of Lily Kimble. Primer pursues a hunch that Dickie Erskine might be Lily's killer but he rules this out after checking with Sergeant MacAuley in Scotland. Primer is present at the denouement with Miss Marple to arrest Dr Kennedy after he confesses.
NHK's Anime adaptation
Inspector Primer also appears in NHK's anime adaptation of Sleeping Murder where he also takes on the role and lines of Inspector Last. The voice actor behind the character is not credited.