It follows an incident in the Caddy Road area of Randalstown, Co Antrim which is believed to have involved a number of vehicles.
Detectives have not said whether he was shot or died as a result of a vicious assault.
And it is not yet known if the murder is in anyway connected to the shooting dead on Monday night by the UDA of Brian McIlhagga, 42, in Ballymoney.
Police are looking at all lines of inquiry.
Detective Chief Inspector Gareth Talbot said: “The incident was reported to police shortly after midnight on Thursday 8 January.
“A woman, aged in her 50s, was also assaulted and has been taken to hospital for treatment to her injuries which are not believed to be life threatening.
“At this time investigations are at an early stage but I am treating this as murder.
“I appeal to anyone who noticed any suspicious vehicles or activity in the Caddy Road area at around midnight to contact CID at Ballymena Police Station on the non emergency number 101.
“Or if someone would prefer to provide information without giving their details, they can contact the independent charity Crimestoppers and speak to them anonymously on 0800 555 111.”