The man accused of killing a Long Beach firefighter is a retired civil engineer who mysteriously lost touch with at least part of his family decades ago, according to his brother.

In a phone interview, George Kim said he was shocked to learn Monday that his younger brother, 77-year-old Thomas Kim, was still alive and that he’d been arrested on suspicion of shooting three people, including two firefighters, at a Long Beach senior-living home.

“I thought he was dead,” George Kim said. “In 30 years, I hadn’t heard from him.”

At a press conference Monday, police said they suspect Thomas Kim set fire to his unit at the 11-story apartment building and then shot the two firefighters as they responded.

Police allege he also wounded a third man, identified only as a resident of the building who was in critical but stable condition.

Based on preliminary evidence, detectives believe Thomas Kim may have set the fires to lure the firefighters into the building at Fourth Street and Atlantic Avenue, LBPD Chief Robert Luna said at the news conference.

“That is one option that we’re looking at, and that will be investigated because obviously if that’s the case, we want to know why,” Luna said.

Thomas Kim did not harbor any kind of animosity toward authorities, George Kim said.

“He’s not involved in any kind of violence, not that kind of person,” George Kim said.

LBFD Capt. David Rosa, a 17-year veteran of the force, was killed in the attack, according to authorities. A second firefighter, Ernesto Torres, 35, was grazed by the gunfire, fire officials said. 

Police said they found two suspicious devices in Thomas Kim’s unit at the 11-story Covenant Manor apartment building after an explosion there prompted a large emergency response.

Thomas Kim was still at the building when police arrived, and they quickly took him into custody, Luna said. He was being held in lieu of $2 million bail on suspicion of murder, arson and two counts of attempted murder. Soon, detectives are expected to present the case to prosecutors who will decide what if any formal charges Thomas Kim will face.

George Kim, who lives in Southern California, said he lost contact with his brother decades ago while Thomas Kim was on a business trip to Mexico. He said the two brother moved to the U.S. from South Korea to study in the 1960s.

Thomas Kim graduated from Cal State Los Angeles and got a job in civil engineering, according to his brother. He married a nurse, but the two got divorced over Thomas Kim’s gambling, according to his brother.

The couple also had a daughter, but George Kim said he hasn’t talked to her in years either.

For a time, Thomas Kim worked in construction in Saudi Arabia and Korea but later moved back to the U.S., George Kim said.

Thomas Kim was usually quiet, according to his brother. George Kim said he remembers a few times when his brother would be sitting quietly and then suddenly have an outburst of emotion or get up and walk outside.

“He doesn’t talk too much, but he’s thinking so many things,” he said.

George Kim said he’s skeptical of police’s suspicion that his brother may have set the fires to lure in first-responders.

“I think he lost his mind momentarily, not on purpose or anything like that,” he said.

Police said they are still trying to learn more about Thomas Kim’s background. At Monday’s news conference, Luna said police have so far found one arrest in his past, which was on suspicion of auto theft many years ago.

“We’re looking at every angle right now,” Luna said. “ … We are digging and we are digging deep.”

Jeremiah Dobruck is managing editor of the Long Beach Post. Reach him at [email protected] or @jeremiahdobruck on Twitter.