Craig Mirfield’s killing in Leeds was the first murder in a trail of shootings, between March and July last year, which shocked the city and left three more people dead.
His death came three days after a doorman at the Chained Bull pub in Moortown was blasted in the legs. In following incidents another nine people were injured.
A month after Mr Mirfield’s death, Leeds man Frank Birley, 33, died from a single shot to the head in the Meanwood area.
The bodies of Clifton Bryan, 29, of Chapeltown, Leeds, and Dennis Wilson, 32, from Manchester, were found in a P-registered Rover car dumped in Darfield Street, Harehills, last May. They had been shot in the back of the head.
Father-of-three Mr Bryan – who had survived two previous shootings in Leeds – and Mr Wilson were found to have died several weeks earlier. Police eventually charged three men from Greater Manchester with committing the murders at a house in Longsight, Manchester.
The house belonged to the parents of Guy Matthews, 27, a courier company boss, who was one of those charged.
The others were Simon Knott, 25, and Roger Rivers, 35.
Matthews, of Woodley, Stockport, made a dramatic confession to the killings in Durham Prison during the subsequent trial, but he later withdrew it.
However, he admitted driving the bodies to Leeds in Mr Bryan’s car and dumping it in Harehills, as well as burning bloodstained clothes and a carpet. He said his aim was to decoy police away from his mother's home.
Knott, a mobile hairdresser, and Rivers, a former haulage contractor, both of Manchester, denied any part in the killing.
A three-week trial at Teesside Crown Court in Middlesbrough ended with not guilty verdicts on the three.
The verdict on Matthews led to angry scenes in court, as a woman shouted from the public gallery: “He’s admitted killing my son. Is there any justice in this country?”
The case originally opened in Manchester but was stopped by the judge in the third week of the trial. He discharged the jury and ordered a retrial.
After the acquittals, a spokeswoman for West Yorkshire Police said any decision on how the investigation would proceed would be taken by their counterparts in Manchester who had handled the original inquiry.
A Greater Manchester Police spokeswoman said: “We will be reviewing our case files and speaking to the Crown Prosecution Service.”