Police have renewed an appeal for information on the 25th anniversary of the murder of Gavin Brett, who was shot dead in a drive-by attack in Glengormley on 29 July 2001.

The 18-year-old was standing with friends near the entrance of a GAA club on Hollybrook Road when a dark-coloured saloon car approached from the Upper Hightown Road direction. An occupant fired a number of shots towards the group, striking Gavin twice. He died at the scene despite medical treatment. A second 18-year-old man was treated in hospital for a gunshot wound to his ankle.

Loyalist gunmen carried out the attack believing Gavin was Catholic because he was with Catholic friends. No one has been convicted of the murder.

Gavin's father, Michael Brett, was a paramedic. He responded to the call to Hightown Road that night, unaware the victim was his own son. He attempted to save him but was unable to do so. In a 2009 interview, his widow Phyllis said Michael never forgave himself and that his premature death in 2007 was linked to the loss of their son.

Gavin's brother is Philip Brett, the DUP MLA for North Belfast. On the anniversary, the victims' group SEFF renewed its appeal for anyone with information to come forward.

DUP MP Carla Lockhart said Gavin was murdered by so-called loyalists and that her thoughts are with the family. She described the killing as a futile act of terrorism.

Detective Chief Inspector Byrne of the Legacy Investigation Branch said two gunmen were involved. A Vauxhall vehicle was seen driving recklessly at Sandyknowes Roundabout shortly before the attack. The following day, a dark blue Vauxhall Nova saloon was found burnt out behind shops at Ballyearl Drive in New Mossley. Police believe the car was linked to the murder.

A number of suspects have been arrested over the years, but no one has been convicted. DCI Byrne said the attack was brutal and harrowing, and that Gavin's father died without seeing his son's killers brought to justice. He urged anyone who now feels able to talk to contact police on 101, submit information online via the PSNI website, or call Crimestoppers anonymously.