The incident occurred at a meat market in the 11000 block of Atlantic Avenue around 7 p.m.
One of a pair of Good Samaritans was able to stab the robber in the neck. The suspect opened fire before fleeing.
One of the victims suffered a gravely critical wound to the head, according to friends. Authorities said he was not expected to survive his injuries. That victim was pronounced dead Wednesday morning at Saint Francis Hospital in Lynwood.
The second victim suffered a small, non-life threatening injury to his arm.
The shooter was last seen getting into an awaiting vehicle, described as a 1996 to 2002 white Chevrolet Astro van with windowless rear cargo doors and an exterior rear mirror.
Later Sunday night, a man was dropped off at a hospital with a stab wound to the neck. According to the Los Angeles County Sheriff's Department, he was identified as the suspect who robbed the meat market. Further investigation led authorities to the van, the driver of the van and a third person who allegedly helped facilitate the robbery.
The shooter was determined to be Lynwood resident Kyle Henderson, 30. He was arrested at Arcadia Hospital and is currently on parole.
The suspect who drove the van was identified as Lynwood resident Terrance Fair, 47, also on parole.
The third suspect was identified as Lynwood resident Ischa Criner, 42.
All three suspects were being charged with murder and were being held without bail. It was originally reported the gravely critical victim had died.
All three suspects were being book at Century Regional Detention Facility.
Neighbors who know the gravely injured man described him as a caring person.
"That's the way he was. He was a very caring person, a very helpful person," said Adriana Lozano.
Anyone with information related to the case is asked to contact the Los Angeles County Sheriff's Department at (323) 890-5500.