Halifax police are once again pleading with witnesses to come forward to help them solve the seven-year-old murder of Jason MacCullough.

MacCullough, a 19-year-old Boys and Girls Club volunteer, was shot in the back of the head while walking home near Pinecrest Drive in Dartmouth on Aug. 28, 1999.

Police officers found his body on a paved path around 2:30 a.m.

Investigators believe MacCullough was the victim of a random act of violence and that a number of people were in the area at the time, said a spokesman for Halifax Regional Police.

"We know there are persons out there with information in relation to what happened," said Const. Jeff Carr.

"Maybe I would ask those people to put themselves in a position where if Jason MacCullough had been one of their family members, what would they want? I think that they would want to see this horrific crime solved."

Over the years, police have made several public appeals for information and have urgedpossible witnesses to come forward.

In April 2005, police said they received new information and launched a search for a woman believed to be at the park the night of the shooting.

But to date, no one has been chargedin MacCullough's shooting.

Carr said the case will not move forward until police find a witness. Witnesses, he added, will not be charged with failing to report the crime.