The PSNI said that Thomas McCabe, 59, had been allowed out on day release from prison but did not return. Detective Inspector Bell said of McCabe, who was sentenced to life for murder in 1990: "He was due to return on August 23 but has failed to so do.
"He is described as around 5ft 8in tall, of medium build with short grey-coloured hair. He was last seen wearing a grey top, blue jeans and grey trainers. "We believe he has connections to Dublin, Newry and Newtownabbey.
"I would appeal to anyone who has seen Thomas McCabe, or who knows of his whereabouts, to contact us on 101. "I would also appeal directly to him directly to hand himself in.
"Alternatively, information can also be provided to the independent charity Crimestoppers on 0800 555 111 which is 100% anonymous."