A man was arrested by three armed officers at gunpoint on Brighton beach last week.
Two men seated just next to the suspect also put their hands up in the air as officers pointed the gun at the man on the shingle.
Sussex Police said he was being arrested in connection with a serious assault near Worthing last month.
A passer-by, who took this picture, said: “It’s not really what you expect when going for a run.
“All I heard was ‘Get on the floor’ shouted a few times.
“The Lib Dem conference had finished but there were lots of armed police around.
“The guy they arrested was on the floor. The two guys sitting in chairs were just enjoying the beach – hence the thumbs up from one of them.”
A spokesman for Sussex Police said: “Armed police attended the beach, Kings Road at around 5.30pm on 17 September to conduct an arrest attempt on a 37-year-old man who was wanted in relation to a serious assault in Clapham, near Worthing.“The reported incident took place on 17 August.
“Officers have thanked the public for their patience while they responded to this incident, which was unrelated to the event taking place at the Brighton Centre.”
Luke Maddran, 37, of no fixed address, was later charged with actual bodily harm, controlling and coercive behaviour, non-fatal strangulation and sending communications threatening death in relation to a 20-something woman.
He appeared before Brighton Magistrates Court on Thursday, 19 September and was remanded in custody.