A gunman who led police on a high-speed chase and daylong, multi-parish manhunt is in custody and unharmed, officials said. 

Matthew Mire, 31, was arrested late Saturday following a shootout with a Louisiana State Police trooper and after leading police on a massive search in response to two overnight shootings that left one dead and three others wounded.

A state trooper, identified as 19-year State Police veteran Adam Gaubert, was later found dead in his vehicle in Prairieville — about a mile away from one of the double shootings. Authorities said Gaudet was "ambushed while in his patrol unit" and linked the incident to Mire, though it was unclear when exactly the trooper was shot.

"This is one of the toughest nights of my entire career," State Police Col. Lamar Davis said in a midnight news conference from the scene. "It hurts, but we will get through it."

The Ascension double shooting was one of two that authorities linked to Mire overnight Saturday. He allegedly shot two neighbors in French Settlement around midnight, then stole a truck and drove to Prairieville.

In the unincorporated Ascension community, he shot two family members, killing one and leaving another in critical condition.

It was not immediately clear when the shooting that killed the trooper occurred or how quickly the body was discovered.

In a Facebook post late Saturday, State Police offered condolences.

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"With a heavy heart, Louisiana State Police is announcing the death of Master Trooper Adam Gaubert who was killed in the line of duty," the post read. "Trooper Gaubert, a 19-year veteran of our department, was ambushed while in his patrol unit."

The social media update asked people to give his family privacy as they grieve.

Mire disappeared into a wooded area off Hoo Shoo Too Road in the southeast corner of East Baton Rouge Parish before dawn Saturday and somehow evaded capture throughout the day.

Officials described the man as "armed and dangerous" and a "person of interest" in the overnight shootings. Police said he was wearing camouflage.

The pursuit started when troopers tried to pull him over around 5 a.m. at La. 42 near Oak Grove Community Center in Prairieville. Instead of stopping, he opened fire and led police on a high-speed chase in a stolen blue Chevrolet Silverado, proceeding a few miles north on Jefferson Highway and crossing into East Baton Rouge.

Mire then turned onto Hoo Shoo Too Road. He drove for about 5 miles before ditching the truck in the side yard of a house, near where the road dead-ends by the Amite River.

From there, he fled on foot into a wooded area.

By 10 p.m., authorities said they finally caught up to Mire, ending the search about 20 hours after the first shots were fired. 

"So, we don't have to worry about him tonight," Ascension Parish Sheriff Bobby Webre said at a late Saturday press conference in Prairieville. "We're so glad we got him in custody tonight, so the manhunt is complete, the investigation is just beginning."

Email Lea Skene at lskene@theadvocate.com.