The owner opened fire, hitting two men. They were both taken to a nearby hospital, where one later died.
"The owner of the businesses ended up firing at the suspects," said Capt. Rick Wall of the Los Angeles Police Department. "One was fatally shot in the chest, two others were wounded and a fourth suspect took off running on foot."
One suspect was arrested when he collapsed at a park across the street from the shop.
The fourth suspect, who was uninjured, was taken into custody a block away.
Investigators are now looking into whether the suspects are responsible for another jewelry store heist about a block away.
Some shop owners nearby said they would have reacted the same way. One man
A man who frequents the shops in the area said he doesn't blame the store owner.
"I'd probably defend myself," said the man, who didn't want to be identified. "Defend myself and do what I've got to do." Police advise people in those situations to be nonconfrontational.
"Go with the flow, cooperate, give the property up," Wall said. "Let the people get out of the door and then call the police. Let us wrap it up and catch the bad guys and put them in jail."
Authorities said it will be determined later whether the store owner will face any charges.
Anyone with information is urged to call the LAPD Harbor Station at (310) 726-7700.