Tucson, AZ – A deputy U.S. Marshal was murdered in the line of duty on Thursday night as he was serving a warrant on a suspect for charges of stalking a law enforcement officer.

“This is a tragic night for law enforcement in Tucson and… across the state of Arizona,” Tucson Police Chief Chris Magnus said during a press conference. “Tonight, a U.S. Marshal was shot and killed while serving a Tucson Police Department active felony warrant.”

The fatal altercation occurred at a residence in the 2600-block of North 15th Avenue at approximately 5:30 p.m.

As several marshals attempted to arrest 26-year-old Ryan Schlesinger on the felony warrant, he opened fire, hitting one of them, Chief Magnus said.

The federal agents immediately returned fire, but Schlesinger was not struck.

The gunman then barricaded himself inside the single-story residence.

The wounded marshal was rushed to Banner-University Medical Center, where he was pronounced dead.

His name has not yet been released.

Tucson police surrounded Schlesinger’s residence immediately after the shooting, and evacuated residents from nearby homes.

Schlesinger surrendered to police without further incident following an hour-long standoff.

“I am presenting this information with a very heavy heart,” Chief Magnus said. “This is a great tragedy, and our hearts go out to this marshal’s family.”

“As you can imagine, they’re devastated,” the chief said of the marshals who were with the fallen hero when the shooting occurred. “I’m sure they’re having a very tough time, as any group of law enforcement officers would.”

Chief Magnus did not provide details regarding the circumstances of stalking charges against Schlesinger, but said that serving a warrant can be a particularly dangerous task for law enforcement officers.

“You never really know how somebody is going to react to that,” he said. “Obviously, a warrant still means that somebody has their day in court, but there are times when the individual being served doesn’t see it that way, and you really don’t know what’s going through their head when they make a decision to do something like this.”

Tucson police and multiple federal law enforcement agencies are working cooperatively to handle the ongoing investigation, the chief said.