A missing FBI agent from Burbank, believed to be suicidal and possibly carrying a handgun, has become the subject of a major manhunt this weekend.

Stephen Ivens, 35, a Los Angeles-based agent specializing in national security, was last seen Friday at his home in the 1700 block of Scott Road in Burbank. He may have headed into the rugged Verdugo Mountains, officials said. Also missing from the home he shared with his wife and 1-year-old son is his handgun, officials said.

Officials would not reveal why they believe Ivens may be suicidal.

“He’s been a valuable member of our office,” said FBI Special Agent Steve Gomez.

A 40-member search-and-rescue team from the Los Angeles County Sheriff's Department along with a dozen Burbank police officers were assisting about 100 FBI agents in the search, officials said.

It was the largest search in Burbank in 20 years, said Capt. Denis Cremins of the Burbank Police Department.

Ivens has been with the FBI for more than three years and before that spent eight years with the Los Angeles Police Department.

Ivens, an avid hiker, left his house on foot. Bloodhounds tracked his scent toward the Verdugo Mountains, Gomez said.