Donnie Finnerman was a local mechanic in the state of Maine. He became Raphael's vessel during a riot involving demons near a gas station.
Season 5
In Free to Be You and Me, Raphael inhabits Donnie Finnerman's body during a conflict with demons at a gas station in Maine, where he decimates the station's structure and destroys the demons there. After Raphael resolved the problem, he abandoned his vessel, retreating to Heaven, leaving Donnie in catatonic-state. He is escorted to St. Pete's Hospital where he is approached by Dean and Castiel. Castiel surrounds Donnie in a Holy Fire circle and performs a summoning ritual, attempting to summon Raphael back to his vessel but it is unsuccessful.
Raphael later re-inhabits Donnie's body at Dean and Castiel's apartment where they trap him and interrogate him for God's location. After he continues to deny knowing God's whereabouts, claiming that He is dead, they leave him there.
Season 6
In The Third Man, Raphael eventually manages to escape the circle and seeks out God's weapons (still using Donnie's body) with a group of angels known as the "traditionalists". He later locates Dean, Sam and Castiel, where he approaches Castiel and and attempts to kill, but Balthazar intervenes and turns Raphael's vessel into a pillar of salt using Lot's Salt, forcing Raphael out of his vessel. Donnie Finnerman is killed in the process.