Dakota Kimbler is charged as an adult and faces a preliminary count of attempted murder. He was being held without bail at the county jail.
The shooting victim told investigators he finished his shift at Paragon Medical in Pierceton at 7 a.m. and left for home in his car, the prosecutor's office said in a news release.
After leaving Kosciusko County and entering Whitley County, the man noticed that someone was in his back seat.
He turned to confront the person, and the person shot him in the chest, the prosecutor's office said.
Despite his wound, the man managed to wrestle the gun from the shooter and held him at gunpoint while he called police and awaited their arrival.
The Whitley County Sheriff's Department and Indiana State Police went to Indiana 5 and West Old Trail Road, west of Larwill, where they found the man and the alleged shooter, later identified as Kimbler.
The prosecutor's office said a handgun was recovered at the scene.
A sheriff's department dispatcher said authorities do not know how Kimbler obtained the gun.
The victim was taken to a hospital. He was not identified, and his condition was not released.
But the dispatcher said he was expected to survive.
Kimbler was arrested, and investigators learned that he had run away from the Pierceton Woods detention facility on Saturday night, the prosecutor's office said.
It was not clear how Kimbler escaped the detention facility, which is less than a mile from the victim's workplace in Pierceton.
A phone message left for a representative of the detention facility was not immediately returned Sunday.