LONG BEACH (CBSLA) — Geo Kim says he didn’t know if his younger brother was alive until Monday night.

“I haven’t seen my brother Thomas Kim – almost 30 years,” Geo Kim said.

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At 77, Thomas Kim was arrested Monday in the shooting death of Long Beach fire Capt. Davis Rosa during an investigation of reports of an explosion at a high-rise senior center.

For his family, the arrest of Thomas Man Kim came as stunning news.

“He’s alive?” his brother asked. “Really, I was so surprised.”

Geo says his brother graduated from Cal State Los Angeles with a degree in civil engineering.

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Thomas had been married – with a daughter. The older brother who now lives in Reseda says Thomas’ wife divorced him.

Geo says the brothers lost touch after Thomas moved back and forth between the United States and Mexico.

He had no idea his brother was in Long Beach.

He says he’s surprised that his brother, who used to attended church regularly, could be arrested in the shooting death.

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“I didn’t believe it because he’s a very peaceful man,” Geo Kim said. “I don’t understand. That’s why I have to go see him. I have to go get the information about this case.”