Thomas Kim, the man facing murder charges in the killing of Long Beach Fire Capt. David Rosa, died in jail on Sunday, officials said.

Thomas Man Kim, 77, died at 3:20 a.m. at the jail ward at County-USC Medical Center, officials said. He succumbed from a previous medical condition, said Nicole Nishida, a spokeswoman for the Sheriff's Department.

Kim allegedly set off an explosive device in his apartment in a effort to kill a neighbor, according to prosecutors. After firefighters knocked down a resulting fire, Kim allegedly shot Rosa and another firefighter.

Police arrested Kim and recovered a handgun from the scene. Kim had been charged with capital murder and several other counts prior to his death on Sunday morning.

The Long Beach Fire Department issued the following response to the news of Kim's death:

"Although we're devastated that this man will never stand trial for the murder that he committed, our focus remains on protecting the Rosa family and the memory of the many honorable and loving contributions that Captain Rosa made to his family and the community.

"We request that you please respect the privacy of the Rosa family at this difficult time.”