Two police officers were shot at point-blank range in an ambush while they were eating lunch in Las Vegas.
The attackers, a man and a woman, walked into CiCi's Pizza on Sunday and gunned down officers Alyn Beck, 41, and Igor Soldo, 31. One of the officers was able to fire back before he died, but it was unclear if he hit the suspects.
Witnesses said one of the shooters shouted "this is a revolution” but a motive remains under investigation, Las Vegas police spokesman Larry Hadfield told The Associated Press.
Police are reportedly investigating the couple's links to the white supremacy movement and found swastika symbols during a search of their home.
Investigators told the Las Vegas Review-Journal the attackers draped the officers' bodies with cloth showing a Revolutionary War-era flag and stripped them of weapons and badges.
The Gadsden flag, a yellow banner with a coiled snake above the words “don’t tread on me” is associated with America's controversial Tea Party movement.
Police had little information on the suspects at the time.
The attackers, a man and a woman, fled to a nearby Wal-Mart supermarket, where they shot a passing shopper dead and took refuge in the back of the store.
According to Las Vegas police, officers entered the building and exchanged gunfire with the suspects, before another round of shots was heard.
It is believed the woman shot the man before turning the gun on herself, in an apparent suicide pact.
The dead shopper's identity has not been confirmed, and the suspects' names were not released.
Neighbours told the Review-Journal the man's name was Jared and described the couple as "militants", who talked of plans to kill police officers.
They were believed to live together and have links to white supremacist movements.
Mr Beck had been with the force since 2001 and had a wife and three children, a statement said. Mr Soldo had been an officer since 2006 and leaves behind his wife and baby.
Pauline Pacheco was shopping at Wal-Mart when she saw the armed man and grabbed her father to escape, KLAS-TV reported.
“We saw when the man was walking, he was shouting, yelling bad words, and suddenly he had a gun,” she told the station. “It was terrible, it was terrible. That man was crazy.”
Assistant Sheriff Kevin McMahill said the male suspect yelled “everyone get out” before shooting at Wal-Mart.
Brian Sandoval, the Governor of Nevada, said he was devastated by the murders, calling them an "act of senseless violence".
Las Vegas' Mayor, Carolyn Goodman, called the killings a “cruel act” and praised the officers for dedicating “their lives to protecting all of us".
A spokesman for Wal-Mart expressed the chain's condolences and said the company is working with police on the investigation. Cici's Pizza also said the company was deeply saddened by the shooting was closing the restaurant until further notice.
Sunday's killings come less than a year after the Las Vegas police department's most recent death on duty. Officer David VanBuskirk died after falling from a helicopter winch while rescuing a stranded hiker in July 2013.
Additional reporting by APReuse content