Noor was killed with a Stanley knife wielded by Charlotte and struck with a hammer by Linda following a confrontation with the sisters and their mother, Kathleen Mulhall.
His head and penis were sliced off and the rest of his corpse dismembered and dumped in the Royal Canal in Dublin where a piece of leg, still wearing a sock, was spotted floating near Croke Park 10 days later.
The subsequent manhunt and the trial in October 2006 attracted intense media attention as the details of the crime slowly emerged.
When Charlotte and Linda were charged with murder in December 2005, their father, John Mulhall, hanged himself in Phoenix Park.
[1][2][3] Justice Paul Carney, presiding over the trial, said during sentencing that it was "the most grotesque killing that has occurred in my professional lifetime".
She pleaded guilty to helping clean up the crime scene to conceal evidence and was sentenced to five years in prison in May 2009.
It was said by the Irish Independent's legal affairs correspondent, Dearbhail McDonald, to have "fuelled fears of ritual killings in Ireland".
The Department of Justice, Equality and Law Reform ordered that he be deported but he appealed and was granted Irish citizenship in March 1999 because he had become the father of an Irish-born child.
[14] The killing took place at a flat Kathleen Mulhall was renting in a house on Richmond Cottages, Summerhill, on 20 March 2005.
[15] On the day of the killing, Linda, Charlotte, their mother and Farah Swaleh Noor had been drinking heavily in Dublin city centre.
Charlotte picked up a Stanley knife and struck Noor across the throat, inflicting a wound that sent him to the ground.
The head was brought by bus to Tallaght where they walked through The Square Shopping Centre to Sean Walsh Memorial Park.
[8] The killing only came to light ten days later when Noor's leg, with a sock on the end, was seen floating in the canal, a few hundred yards from Croke Park.
That key witness, a Somali man who was the first to connect the missing Noor with the three Mulhall women, was paid a "substantial" reward by Crimestoppers.
When Gardaí searched the Mulhall flat in Summerhill, they found bloodstains that were later confirmed to match Noor's DNA.
[8][18] After Linda's confession, Kathleen Mulhall fled the country in September 2005 and gardaí were unable to locate her again until January 2008.
[21] Charlotte Mulhall requested leave to appeal her conviction on the grounds that Justice Carney had put pressure on the jury to reach a verdict even though the foreman had indicated they were deadlocked.
[22] This failed on the grounds that the defence did not raise objections to the comments during the trial and the fact that the jury was not affected by any alleged undue pressure to reach a verdict.
[2] Linda Mulhall turned to alcohol and slashed her arms, causing her to spend over a week in a psychiatric hospital.
[8] In April 2009, she claimed to fellow inmates that she had in fact smashed Noor's head and distributed the fragments in rubbish bins in the Phoenix Park.
[3] This first disclosure of where Noor's head had ended up was referred to as "the final secret of the Scissor Sisters" by Cormac Looney in the Evening Herald.
Several books were written on the circumstances surrounding the death of Farah Swaleh Noor: The 2009 RTÉ television series Killers featured the Mulhall sisters.