Police on Tuesday charged Deshawn Thomas with murder after another man, David Saldana, was shot dead in a St. Louis street on Monday.
St. Louis police said they detained Thomas, aged 23, outside the city’s public library on Olive Street, after he ran from the scene of the crime.
The shooting, which took place shortly after 10 a.m. by the sidewalk in front of the Globe Building, was filmed by a bystander.
In the footage a man can be seen standing over Saldana, who is sitting on the edge of the road and appears to have his hands over his ears.
The man, who seems to speak briefly into his cell phone, loads a pistol then shoots Saldana once in the head, killing him.
When Thomas was later arrested he was found to posses a gun and bullet casing, according to police.
The St Louis Post Dispatch, a local newspaper, said Thomas has been charged with first-degree murder and armed criminal action.
A police mugshot of Thomas shows a lightly bearded man with tattoos on his neck and forehead, wearing what appears to be a red jumper.
There are unconfirmed reports that Thomas and Saldana had earlier had a fight outside a nearby Shell gas station, located in 700 block of North Tucker Boulevard.
It is unclear if the two men already knew each other, and little information has been publicly made available about the suspect.
The video clip showing the shooting was uploaded to Twitter several times before being removed from the platform.