Detectives investigating the murder of a man in a west Belfast gun attack at the weekend have made a fourth arrest.
Edward Gibson was shot in his stomach and thigh in an alleyway beside Divis Tower on Friday and died in hospital.
Officers arrested a 57-year-old man in west Belfast on Monday afternoon.
They are also continuing to question a 30-year-old man who was one of three people arrested shortly after the attack. The two others were released.
The 30-year-old man has been receiving hospital treatment for stab wounds.
The others, a 31-year-old woman and a 33-year-old man, were released on Sunday pending a report to the Public Prosecution Service.
Police said they did not believe dissident republicans were involved in the attack, but have not ruled out a punishment-style attack.