Detectives investigating McNally's cold-blooded shooting in the first gang murder of the year now believe the chief suspect also killed his brother in February, 2009

. And, that the gun-for-hire carried out the pub murder of Paul ‘Farmer' Martin over three years ago. Our CCTV footage shows him entering the Jolly Toper bar in Finglas to carry out the hit on 39-year-old Martin in August, 2008. Five months later, Graham McNally's body was found in a ditch on the former Dublin to Derry road -- he had been shot at least five times in the head. "There are links to suggest that all three murders were carried out by the same man," said a source. "Alan McNally's fatal mistake was when he swore to avenge his brother's death." SHOT He was shot six times in the Cappagh Nua pub in Finglas on February 2 in a killing that was dubbed the Love/Hate murder because of its similarly to a scene from the RTE drama. As the garda probe intensified they questioned a sister and niece of the chief suspect but they were later released without charge. Detectives made a major breakthrough in the case when they obtained CCTV linking relatives of the chief suspect to the crime scene. However, they have still not recovered the handgun used to shoot Alan McNally six times. The Herald previously revealed that McNally was murdered on the order of a violent thug who himself survived an assassination attempt in December 2010. McNally (36), from Cappagh Avenue, Finglas, had been warned by gardai that his life was under threat after rowing with criminal elements in Finglas and Coolock. He had been warned by gardai to be inconspicuous as they feared there was an imminent danger to his life. However, sources say that he ignored gardai and publicly boasted about getting revenge for his brother's death. This is thought to have led his killers to adopt a "let's get him first" approach. Graham was 34 when he was shot dead by slain crimelord Eamon 'The Don' Dunne's gang in January 2009. Alan was in jail at the time after he had a falling out with his former close associate Dunne who had suspected that he was trying to murder him. He was only released last October having served five and a half years for having €200,000 worth of heroin. Sources say that despite the warnings he made himself an easy target for a gunman by drinking in the same pub for 14 hours. Gardai are anxious to apprehend the hitman who could also be responsible for other gangland assaults in the city. 'Farmer' Martin was a known criminal believed to have been involved in over a dozen bank robberies in the late 1980s and 1990s. Speaking at his funeral, Paul Martin's local priest branded his killers as "sick people not fit to be called men".