The feud that sparked slaughter in city streets
David Byrne (34) was shot dead when four gunmen busted into the Regency hotel on February 5.
Two others were also left seriously injured after the gunmen, dressed as armed SWAT gardaí and an elderly woman, opened fire in the Dublin hotel.
The gang stormed the hotel which was hosting a boxing weigh-in ahead of a European title fight.
Several members of the deadly Kinahan cartel were present at the weigh-in.
David Byrne, from Crumlin, was considered to be one of Dublin's most notorious drug dealers and was a key member of the Kinahan cartel.
However, he was not the main target for the hitmen.
One of the Regency hotel gunmen, a man dressed as a woman, later ran out of the hotel and shouted: "He's not f****** here. I can't find him."
The drag was wearing a blonde wig. The other hitman is now known as 'Flatcap' for his stocky build and infamous beige cap.
Two of the other hitmen were armed with AK47 automatic weapons.
More than 300 people - including several children - were attending the Clash of the Clans event in the hotel when the shooting occurred at around 2.20pm.
Within seconds of the shocking shooting, the six-man hit-team sped out of the car park in a white van, having carried out the callous murder.
The hotel shooting was understood to be in retaliation for the murder of Gary Hutch in Spain last year.
The 33-year-old, a nephew of Gerry 'The Monk' Hutch, fled to Spain last year.
However, his life was cut short after he was shot dead by a gunman who chased him around a swimming pool.
The criminal was thought to be a key member of the Kinahan cartel, but he had a fallen out with leaders of the gang.
Eyewitnesses later described how they fled for their lives during the shooting at the Regency hotel.
A little child could be heard screaming in footage from the hotel: "Daddy, help me. Daddy, what was that?"
The three AK-47 assault rifles suspected of being used in the hotel gun attack were seized by gardaí in March.
The weapons were discovered after gardaí searched a car in Slane, Co Meath.
The seizure was considered as a first major development in the case since the shooting.
Eddie Hutch, who is the brother of Gerry 'The Monk' Hutch, was murdered on February 8 - three days after the gunmen stormed the Regency and murdered Byrne.
Noel 'Kingsize' Duggan (56) was also shot dead as he sat in his car at his home in Meath on March 23.
He became a primary target for the Kinahan cartel because of his long-standing business and personal relationship with their arch enemy - 'The Monk'.
The feud has also claimed the life of homeless man Martin O'Rourke, who was gunned down in a case of mistaken identity in Dublin's north-inner city.
Publican Michael Barr (35) was also shot in the head in front of several people at The Sunset House pub in Summerhill, Dublin, in April.