Matthew Langdon was a former NYPD Detective. He worked for corrupt NYPD Lieutenant Melanie Hawkins.
Throughout the Series[]
Langdon had a stellar 14 year career in the NYPD before joining Hawkin's squad in 2010. He worked for her for 3 months and then quit the force entirely. He took himself off the grid, moving to a hog farm in Pennsylvania, and his wife filed a missing persons report. Though later he would claim that he was forced to leave once he saw Hawkins making deals with a gang leader and was threatened, in reality he would still work for her, using his pig farm as a cover to smuggle illicit goods (for example diamonds fed in the pigs). In addition, he would provide a shell corporation, "Flaxton Hill Holdings", to move their money. He would also receive sporadic visits from his wife.
Season Four[]
With one last day to find evidence Jake finds Langdon's name as a member of Hawkins' squad that was overlooked, owing to having never signed an arrest report.
Jake Peralta found a photo posted by his wife that was geotagged at the location of Flaxton Hill Farms in Horseditch, Pennsylvania. He and Amy Santiago visit Langdon at his farm in hopes of getting him to testify against Hawkins.
He explains that he worked with Hawkins years ago and found her corruption, to which she threatened his life if he didn't flee. While initially adamant to participate, he decides to help them.
In the trial, Jake brings Langdon to testify against Hawkins. However, Terry and Boyle discover that Langdon was the one who sent the money to the bank accounts just as he begins his testimony. Langdon commits perjury and testifies against Jake and Rosa, claiming Jake paid him $300,000 to testify. After consideration, the jury finds Jake and Rosa guilty.
Season Five[]
He is mentioned in The Big House Pt. 2 by Raymond Holt during Hawkins' arrest as having confessed.