In the pre-dawn hours of September 26, 1993, Boston Police detective John James Mulligan, 52, was found slumped in his Ford Explorer in the Walgreens parking lot in Roslindale. Mulligan, a 27-year department veteran working a paid security detail, had been shot five times in the face in what was described as an execution-style killing. There were no signs of a struggle, no broken windows, and his service weapon was missing from its holster.

Initial investigation explored the possibility of revenge tied to Mulligan’s controversial reputation and numerous civilian complaints, but attention later turned to two local youths, 19-year-old Sean Ellis and 18-year-old Terry Patterson, who investigators said had killed Mulligan to steal his gun. Both men were convicted of first-degree murder in 1995. Over the following years allegations emerged about corruption and misconduct by detectives involved in the probe; Patterson’s conviction was overturned in 2000 and he later pleaded to manslaughter and was released in 2007. Ellis’s conviction was also overturned in later proceedings, and questions remain about whether the original investigation was compromised.

Does anyone have information about Mulligan’s final assignment that night or memories of the Roslindale scene?