Police Tuesday released surveillance video of the incident in hopes that someone will recognize the men.
Authorities said three men walked into a 98 Cent Store on the 1300 block of West Venice Boulevard and demanded money from the store owner, who was at the counter with his wife. During the confrontation, one of the suspects pulled out a gun and shot the man in the head.
The sons of the store owner were in a back office doing accounting work at the time of the shooting.
"They heard the shot and came out to find their dad laying on the ground," said LAPD Lt. Joe Losorelli.
The owner's wife and two adult sons were not harmed.
A nearby business owner heard the commotion and ran to help.
"I saw his son walking on the street screaming. He said, 'My dad, my dad, my dad,' and then I took hands and I took him back to the store," said business owner Tommy Baldi.
The owner was well-known in the community as a kind, generous man.
"He treats everybody good, he give out to people, when they need something, for free," Baldi said.
The suspects were last seen fleeing from the store. Police believe they are all gang members.
Anyone with information related to this case is urged to call (877) LAPD-24-7.