MacPherson, a 30-year veteran of the force, had been serving as acting police chief since former chief Thomas LaCroix was arrested for hitting his wife at their Maynard home in 2012. LaCroix later resigned after being convicted.
McCarthy appointed him as the permanent chief in January, choosing him over Capt. Donald Feeney, Capt. Steven Champeon and Capt. William Stanton.