Jenkins is a detective for the Narcotics Division of the El Paso County Sheriff's Office, and was also Martin Riggs' partner in El Paso before Riggs moved to Los Angeles.
Jenkins is first seen with Riggs as they are chasing after some drug dealers in the deserts outside of El Paso. Just when Riggs' wife Miranda calls Riggs, Riggs is distracted and they lose the dealers.
Just then, at a long distance, Riggs and get out his sniper rifle and shoots the dealers in their getaway vehicle.
Right after, Riggs gets a call from the hospital about Miranda, and he and Jenkins go to the hospital. As Riggs mourns the death of his wife Miranda in that six after he's moved to Los Angeles, Jenkins is not seen or heard from again.