On the morning of March 14, 2014, Boston police conducting a welfare check at a Perham Street home in West Roxbury entered through an unlocked second-floor window and found 66-year-old Mark T. Regan dead on the floor, partially covered by a bedsheet. Officers determined he had been shot to death.

Officers encountered a 33-year-old adopted son, Mark Tomas Regan, in the house; he said he had been hiding in the attic. Investigators found live and spent cartridge cases in a bedroom used by the son and recovered a .38 caliber Charter Arms revolver hidden in attic insulation. Ballistics testing matched bullets from the elder Regan’s body to that revolver, and the son’s fingerprints were found on the gun. The son was arrested and charged with murder; he was later convicted of second-degree murder and sentenced to life with parole possible after 15 years.

What details about the case or the neighborhood on Perham Street might help explain how this happened or who else could have relevant information?