Police have said that Michael Brown, the black teen who was shot by police on Saturday in Ferguson, Missouri, had just been a suspect in a robbery a few minutes before.
But they said that the robbery at the convenience store had nothing to do with Mr. Brown’s first meeting with the officer who shot him.
The family of Mr. Brown is angry that the police are trying to “justify the execution-style murder,” as they see it.
The killing sparked days of angry clashes between police and protestors.
Thomas Jackson, the chief of police in Ferguson, said that the officer who shot Michael Brown did not know that he had allegedly stolen things from a store nearby.
“The first time the officer talked to Michael Brown, it had nothing to do with the robbery,” he said.
Instead, he said, Brown “was walking down the middle of the street and stopping traffic,” which was why he was stopped.
Mr. Jackson said that the only reason he showed the video of the crime was because journalists had asked for it many times under the Freedom of Information Act.
He said that the robbery at the convenience store had been done without a gun.
A police report shows CCTV pictures of a well-built black man threatening a store clerk.
The man is called Mr. Brown in the police report. He is 6ft 4in (193cm) tall and weighs 292 pounds (132kg).
It says that he “took a box of Swisher Sweet cigars” and gave them to a second suspect named Dorian Johnson, who is Mr. Brown’s friend.
Since the shooting on Saturday, Mr. Johnson has said in a number of interviews that Mr. Brown put his hands up as a sign of surrender before the officer shot him.
Also on Friday, Mr. Jackson said that the officer who shot and killed Mr. Brown was named Darren Wilson and that Mr. Brown hurt him while they were fighting.
Mr. Jackson said that Mr. Wilson has been a police officer for six years and has never been in trouble.