Discretion, tact and dignity are my middle names. I mean, not really. It's actually Fintan. After the little-known St Fintan. You don't need to know that.
Jack Mooney
Detective Inspector Jack Mooney first appears in Death in Paradise since the fifth episode of Series 6.
Jack originally worked for the Metropolitan Police in London until he worked on a case with the team of Honoré Police Station (6:5 Man Overboard - Part One). Humphrey Goodman invited him and his daughter Siobhan to use his shack on the island while he stayed in London with Martha. Jack's wife died only a month ago so Humphrey thought he and Siobhan might want a break.
When a tourist provided an alibi for a woman convicted of murder eight years ago (6:7 In the Footsteps of a Killer), the team were forced to reopen the case. Florence asked Jack to help with the case. Jack ultimately solved the case with the help of the team.
Siobhan and Jack
When Commissioner Selwyn Patterson asked Jack to stay as the permanent Chief of Honoré Police, he knew the only person that could make that choice for him was his daughter Siobhan. After he has solved the murder of a local mayoral candidate and cleared Catherine Bordey's name (6:8 Murder in the Polls), Siobhan gave Jack her blessing and he took up the permanent position as Detective Inspector on Saint Marie.
Jack's technique is to relax people and put them off their guard by telling anecdotes about his seemingly large family. He is also fond of the casual questioning technique, for example flicking through a blank notebook seemingly in search of a small piece of information before asking the killer question.
Jack has a sweet tooth, and is often seen sneaking a sweet, or taking out a packet of tic-tac mints to toss one into his mouth. He is also shown to have an affinity for sausages. He is generally relaxed and laid back but can be quite serious when needed, such as when Detective Sergeant Florence Cassell was shot. He can also be seen openly grieving his wife at times, even having a dinner with a photo of her before going on a date. Because of his grief, he had no real love interests but dated Anna Masani for a short period of time before letting her go. He was also seen flirting slightly with Catherine Bordey, but that never went anywhere.
He adapted to Saint Marie much faster than the other DIs and has happily attended multiple island celebrations and participated in other activities with the team. Jack genuinely cared the island and its people. He in turn was well liked by the entirety of the station and generally got on very well with everyone, even as new people came along like Detective Sergeant Madeleine Dumas. He tried his best to take care of his team and took the time to know them all.
He eventually left the island after he realized that he was only staying on Saint Marie and dating Anna to run away from his grief over his wife. He returned back to London to live in his old apartment and to be closer to Siobhan. He also turned down traveling the world with Anna, guilty over stringing her along. He was replaced by Detective Inspector Neville Parker.