What's the origin of Donald Trump's 'when the looting starts, the shooting starts' tweet?

For the second time in a week, Twitter flagged up a Donald Trump tweet for violating the social media platform's code of conduct.

On May 28 Trump's tweet in question falsely claimed that the governor of California (Democrat Gavin Newsom) was sending out mail-in ballots to "anyone living in the state, no matter who they are or how they got there." Twitter labelled the posts with a message urging users to "get the facts about mail-in ballots." Twitter's message directly linked to a curated fact-checking page populated with journalists and news article summaries debunking the claim.

Floyd reaction

On Monday, 25 May George Floyd was killed in Minneapolis after pleading for help as police officer Derek Chauvin knelt on his neck to pin him down. Floyd was unarmed and already handcuffed. He was pronounced dead at a nearby hospital. Footage shot by a bystander shows Chauvin kneeling on Floyd’s neck, as he pleads that he cannot breath, until he slowly stops talking and moving.

Full screen

The death has provoked widespread protests, initially in the city where Floyd was killed, Minneapolis, but which have now spread across the US.

President Donald Trump tweeted about the protests overnight in Minneapolis but violated Twitter's conduct code in glorifying violence due to line of his post: "When the looting starts, the shooting starts."

The phrase was originally used by Walter Heradley in 1967. Headley was a Miami police chief who served for 20 years with the force.

"There is only one way to handle looters and arsonists during a riot and that is to shoot them on sight. I've let the word filter down: When the looting starts the shooting starts," Headley said, according to a New York Times report from 1970 with Heradley referring to Civil Rights campaigning.