A man killed four people and wounded two in a string of robberies and stabbings in California's Orange County, south of Los Angeles, before he was arrested, police said Wednesday.
It comes just days after mass killings at A Walmart in Texas and a bar in Ohio.
The 33-year-old Garden Grove man was taken into custody after he came out of a 7-Eleven store and dropped a knife and a gun that he had taken from a security guard before fatally stabbing him, police said. His name wasn't immediately released.
One person was attacked so ferociously his nose was almost cut off.
The violence appeared to be random and the only known motives appear to be "robbery, hate, homicide," Garden Grove police Lt. Carl Whitney said at a news conference.
"We know this guy was full of anger and he harmed a lot of people tonight," he said.
The attacks took place over about two hours in Garden Grove and neighbouring Santa Ana, southeast of Los Angeles.
Lt. Whitney said police first answered a burglary report at an apartment, where no one was hurt, he said.
A bakery was then robbed; as was an insurance business and a woman was stabbed several times in the back. She is expected to survive.
A caller reported watching the stabbing from closed-circuit television, Lt. Whitney said.
Police were called back to the same apartment complex, where two men had been stabbed. One died on a balcony and another died at a hospital, he said.
A cheque-cashing business also was robbed, as well as a petrol station where a man was slashed so badly that his nose was nearly severed, Whitney said.
The suspect's silver Mercedes was tracked to the parking lot of a 7-Eleven store in Santa Ana where the security guard was disarmed and fatally stabbed, Whitney said. An employee of a nearby Subway store was also killed.
The suspect and all the victims were Hispanic, Whitney said.