Police investigating the murder of Kevin McAlorum at a south Belfast primary school on Thursday are understood to be following definite lines of inquiry linked to an INLA feud in 1996 and to organised crime.
In north Belfast meanwhile, detectives have been granted more time to detain and question two suspects following the murder of a Chinese woman discovered in the boot of a car, also on Thursday.
It is thought Mr McAlorum's murder could be linked to the murder eight years ago of INLA figure Gino Gallagher.
However, it has not been discounted that Mr McAlorum (31) could have been targeted by gunmen connected to drug-dealing or other forms of organised crime in the west Belfast area.
His attackers rammed his car into a van as he dropped off a pupil at Oakwood integrated primary school in Derriaghy on the southern outskirts of Belfast. They then ran up to his Audi A4 and shot him dead at the wheel. He was shot a number of times in the car and died at the scene. A Nissan Almera, found burning a short distance away, was used by the killers.
Mr McAlorum was an alleged drugs dealer and had INLA connections. He was involved in the INLA feud of 1996 in which six people, including his sister, Barbara (9), were killed.
He had been a republican prisoner and was freed on licence following the signing of the Belfast Agreement in 1998.
A senior member of the Irish Republican Socialist Party told The Irish Times on Thursday that the INLA was not involved in the McAlorum murder.
In north Belfast, PSNI officers investigating the murder of a Chinese woman found dead in a car boot were last night continuing to question two suspects. They are believed to be following a lead linking the killing with a brothel in the city. Another lead suggests a kidnap and ransom plot.
The body of the victim, believed to be in her early 20s, was in boot of a Ford Escort at an Antrim Road filling station.
The arrests were made following a tip-off about suspicious activity outside a house on nearby Skegoneill Avenue.
The body has still not been identified. The dead woman is 5 feet 4 inches tall, of slim build, with shoulder-length black hair and a centre parting. She also had a small birthmark above her knee. A post-mortem examination has been carried out, but police have refused to reveal the exact cause of death. It is understood that reports that the body has been dismembered are being discounted.
Ms Anna Lo, chief executive of the Chinese Welfare Association in Belfast, told the BBC yesterday: "We received a call from the police to say that they seemed to have intelligence to suspect a Chinese gang from London coming to Northern Ireland to attempt kidnapping for ransom."
"A letter was distributed around the community this week. Whether there was any connection with this, nobody knows at this moment," she said.