He was shot to death by a Provisional IRA volunteer from a passing car as he stood outside "The Eagle" chip shop below the offices where the UVF Brigade Staff had their headquarters on the Shankill Road.

Two units from the UVF's Belfast and Mid-Ulster Brigades exploded three no-warning car bombs in Dublin's city centre on 17 May 1974, the third day of the Ulster Workers Council Strike.

According to former British soldier and psychological warfare operative Colin Wallace, the bombings had been organised by Billy Hanna, the Mid-Ulster Brigade's commander at the time.

[8] The three cars used in the attacks had been stolen and hijacked that morning in Belfast by a UVF unit known as "Freddie and the Dreamers" (named after the 1960s English pop group)[9] allegedly led by Marchant, and then, according to the 1993 Yorkshire Television documentary The Hidden Hand: The Forgotten Massacre, driven to a farm in Glenanne, County Armagh.

The Hidden Hand: The Forgotten Massacre named Marchant as having been on a Garda Síochána list of suspects as the leader of the gang which obtained the bomb cars.

[17] Colin Wallace briefed the media without attribution, identifying Marchant as the person responsible for the car hijackings and theft, based on his own information.

When queried by the organisation's legal team, Wallace qualified the statement by adding: That's right, that was my belief … there were a number of Special Branch people who at this time appeared to have very close links with various loyalist groups.

[20] Although he had appeared before Belfast's Crumlin Road Crown Court, the case against him and the others had collapsed when the judge decided Allen's evidence was ""totally unreliable".

[22] In 1984 Marchant, along with fellow UVF man John Bingham, was part of a group led by Loyalist politician George Seawright that wielded legally-held handguns to physically remove an Irish tricolour that had been erected at Whiterock Leisure Centre.

[23] Marchant was shot dead by IRA gunmen from a passing car as he stood outside "The Eagle" chip shop on the crowded Shankill Road on 28 April 1987.

Marchant's fatal shooting was in retaliation for the UVF's killing of Larry Marley, a close friend of Sinn Féin President Gerry Adams and a senior IRA member from Ardoyne, less than a month before.

[26] George Seawright, a member of Belfast City Council who also maintained clandestine UVF membership, stated in the aftermath of Marchant's shooting that he had "no hesitation in calling for revenge and retribution".

[20] Several months after Marchant's shooting, the UVF sought to avenge his death with an attempt on the life of Anthony "Booster" Hughes, a suspected IRA man from Ardoyne.

The UVF conducted an internal inquiry in an attempt to establish whether someone within the organisation had supplied information to the IRA which had led to the killings of Marchant and the other two: Lenny Murphy and John Bingham.