A 16-year-old boy has been arrested on suspicion of robbery after a pensioner was attacked at his home.
Police are also seeking another man over the incident in Burgess Hill on Monday (August 25) in which the pensioner was hit over the head with a crowbar.
The 70-year-old victim answered his door in Windmill Drive and was confronted by two young men, police said.
One of them hit him over the head with a crowbar, demanding money, while the second pointed a handgun at him.
They both ran away when the pensioner grabbed a kitchen knife. He was with his wife at the time and was taken to hospital for treatment to a cut to his head and to his finger.
Detective Sergeant Laura Diamond said on Tuesday: "This was a brutal attack and we are supporting the couple following their ordeal.
"The man opened the door just after 7pm that evening as he thought it was a member of the family visiting and bravely confronted his violent attackers."
The 16-year-old has been bailed until October 29.
Anyone with information is asked to contact police on 101, email firstname.lastname@example.org or call Crimestoppers on 0800 555 111 quoting serial 1161 25/8.