Updated

A man who died after a police shootout along a Missouri interstate this week was a "tortured soul" who finally cracked, relatives said.

Jerrod Kershaw, 31, died Monday after exchanging gunfire with police on Interstate 55 in Jefferson County, about 35 miles south of St. Louis.

His aunt and grandmother told the St. Louis Post-Dispatch that Kershaw hadn't been the same since returning from Iraq, where he served in the U.S. Army for most of 2010. They said he suffered from depression, nearly died this year from complications from a severely abscessed tooth, and was recently diagnosed with diabetes.

Kershaw sought help for depression at John Cochran Veterans Administration Medical Center in St. Louis, according to his aunt, Debra Collins. She said Kershaw seemed better in recent weeks and had decided to stop taking antidepressant medication.

"He would not have hurt anybody," Collins said. "Something made him crack. ... He was a tortured soul."

Investigators said Monday that Kershaw crashed a car in St. Louis County, then carjacked a vehicle from a Good Samaritan who stopped to help. Kershaw then fled down I-55, triggering a police chase.

Around the same time, Kershaw's mother called police to say her son was heading to a nearby city to kill a relative and himself. Then another caller reported that Kershaw had threatened to kill co-workers in Pacific, the St. Louis suburb where he worked and lived, according to Jefferson County Sheriff Dave Marshak.

Officers were able to stop Kershaw's vehicle. He shot at police, and officers returned fire, investigators said. No officers or bystanders were hurt.

Kershaw was later found dead in the car. Authorities haven't said how Kershaw died, but said he was wearing a bulletproof vest and was armed with several guns.

Missouri's online court reporting system doesn't show any criminal record for Kershaw. Marshak said his department had "multiple dealings" with Kershaw in the past, but he didn't elaborate.

Kershaw's grandmother, Dorothy Vilmer, said Kershaw had "been through hell for quite a while now."