(CNN) Authorities have identified a Colorado deputy who was fatally shot Wednesday night after chasing a suspect.

Adams County Deputy Heath Gumm, 31, had been a member of the department for five years, Sheriff Michael McIntosh said. The deputy was wearing a protective vest.

Authorities have a suspect in custody, officials said. McIntosh declined to release the suspect's name.

Deputies had been chasing the man in an "assault in progress" call about 7 p.m. (local time) when they followed him behind a home in Thornton, a city in the Denver metropolitan area.

When deputies approached the man, he pulled out a handgun, firing at them and hitting a deputy in the chest, said Adams County Special Deputy Amanda Overton.

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