There’s a neat background here I learned over on the Scan New England forums. An MSP helicopter crashed in 1995 over Cambridge, killing all four occupants, consisting of two Troopers and two AT&T techs. The last two letters of each of the contemporary helicopters’ tail numbers honor them: Troopers Paul Perry (PP) and James Mattaliano (JM), and technicians Arthur Howell (AH) and Michael McCarthy (MM).
