Nothing is known about Frost's life, except that he was known to be extremely curious, to enjoy danger, to be humorous and optimistic. He was a firearms specialist and service technician also qualified in handling hazardous materials. Due to these skills, Frost was placed in charge of upgrade and maintenance of S.T.A.R.S. Alpha Team. However, although he was an excellent officer, there were concerns about his behavior in emergencies due to his energetic nature. Frost and Kenneth J. Sullivan also were the only officers equipped with a video recording unit during operations.
He was also hated along with Chris and Forest by Brian Irons, the chief of police.
The Mansion Incident and Death
After Bravo team lost contact with R.P.D., Joseph was among the Alpha team members when they discovered the wreckage of Bravo team's helicopter on 24 July 1998. Due to his curiosity in wanting to search the surrounding area for clues about the whereabouts of any of his colleagues, he was the one who finding the partially eaten corpse of Bravo team's pilot, Kevin Dooley.
Whilst searching through the forest, he was distracted by a pack of Cerberuses roaming the Arklay Mountains. Moving away from the rest of Alpha team, he was attacked by a number of Cerberus dogs en masse. Unable to fend off the Cerberus pack, Joseph was overwhelmed and his screams of pain alerted the other members of the unit. The direct cause of his death in addition to his mutilation was a broken spine. Fellow Alpha team member, Jill Valentine, attempted to help, unloading an entire pistol magazine into the pack, with no success. After killing Joseph, they quickly turned to Jill and the other Alpha team members, pursuing them towards the nearby mansion.