Four men arrested yesterday in connection with a PSNI investigation into last week's murder of a man in Armagh have been released without charge.
One person remains in custody.
Police have been examining several possible motives for the murder of Mr Conlon last week, including the possibility that the attack may have been homophobic.
They have also been checking whether he was the victim of a fall-out with former associates linked to the "Real IRA".
The dead man was recently released from a four-year prison sentence in Portlaoise prison for training others in the use of firearms in Co Meath. He
had been one of six men jailed in Dublin in March 2001 after pleading guilty to training people in the use of firearms.
Mr Conlon (35), from Railway Street, Armagh, was found unconscious at the side of Farnaloy Road, outside Keady, at around 6.30pm on November 7th. He was taken to hospital where he later died from several gunshot wounds to his head.
His body was discovered close to the Madden estate outside Keady and about a mile-and-a-half from where his silver Volkswagen Passat car was later found burnt-out.