SUNNYVALE — Police shot and killed a homicide suspect who brandished a gun at them as they tried to serve search and arrest warrants at a home Thursday morning, according to the Sunnyvale Department of Public Safety.

Glen Griggs, 53, was the primary suspect in the May 2013 disappearance of Molly Franquemont, who had been living at 498 N. Fair Oaks Ave. with Griggs when she went missing, according to Sunnyvale Capt. Jeffrey Plecque. As the case continued, Plecque said detectives came to believe Franquemont may have been the victim of a homicide.

Around 9 a.m. Thursday, detectives went to the Fair Oaks Avenue home to serve Griggs with both search and arrest warrants.

When officers knocked on the door to the home, Griggs did not answer, and subsequent repeated attempts to get him to open the door were unsuccessful, Plecque said. Officers then forced their way into the home and were immediately confronted by Griggs, who had barricaded himself inside. He told officers he was armed with a gun.

Officers backed out of the home and continued to try to convince Griggs to surrender, but he refused.

Griggs later began to walk out the back of the house, and officers saw him with what they described as a “long gun” — a general term for firearms in the class of rifles or shotguns — in his hands. They ordered him to drop his weapon. Griggs either ignored them or refused to do so, Plecque said, and in fearing for their safety, the officers opened fire.

Griggs was taken to Valley Medical Center, where he later died from his injuries, Plecque added.

The number of officers who opened fire and their names were not immediately released.

The Sunnyvale Department of Public Safety and the Santa Clara County District Attorney’s Office are conducting a joint investigation into the shooting, which is the county’s protocol.

The department’s Investigation Unit is continuing its criminal investigation into Franquemont’s disappearance.

Traffic near Fair Oaks and Maude avenues was backed up for several hours while officers investigated and cleared the scene of the shooting.

A school in the area was also briefly locked down.

The last officer-involved shooting in Sunnyvale was in August when Michael Nehez was shot by three officers as he rushed at them with a large kitchen knife. Nehez had called 911 and told dispatchers that he had killed his wife, who was later found dead in the home.

In September, Juan Ruelas, of Sunnyvale, was shot while the Santa Clara Police Department and the Drug Enforcement Administration were investigating him after he supplied agents with methamphetamine numerous times over the previous month, police said.

According to Sunnyvale police officials who are investigating the September shooting, undercover officers bought a pound of meth from Ruelas in the parking lot of a Hobee’s Restaurant on West Ahwahnee Avenue south of Highway 101.

“After the pound of methamphetamine was received from Ruelas, he verbally threatened the officer and stated he had a gun,” read a police report. “Ruelas then made a movement that led the officer to believe he was reaching for a gun.”

Ruelas was then shot “several times,” with half a dozen officers firing their weapons, according to the report. No gun was found on Ruelas or in the truck where he was shot.