A woman has been arrested over what police described as a "sickening and despicable" street attack on an 80-year-old man in Coventry.
Images of the incident, released by police, helped prompt a "surge" of responses from the public, police said.
The 19-year-old, from Gloucester, is being questioned by West Midlands Police.
The pensioner received a black eye and bloodied nose after a punch from a woman in the attack on Saturday.
Ch Sup Andy Nicholson said: "This was a sickening, despicable, violent attack on an elderly man in broad daylight."
The pensioner was attacked near Sainsbury's in Coventry's Trinity Street, at around 20:30 BST.
A video of the attack, recorded by a passer-by on their mobile phone, has been circulated on social media.
Police issued a series of still images showing the assault in the hope that witnesses will contact them.