The most senior judge in England and Wales delivered a severe warning against gun crime yesterday as he increased the sentence on the gang member who armed the killer of schoolboy Rhys Jones from seven years to twelve.

James Yates, now 21, was given seven years’ detention at Liverpool Crown Court in January for possession of a prohibited firearm and for assisting the killer, Sean Mercer, 18.

But yesterday Lord Judge, the Lord Chief Justice, increased the sentence, saying that Yates’s “gravest culpability” was in handing over the gun to his friend for reasons of gang warfare and misplaced gang loyalty. It was taken to a public place and “an innocent child was gunned down”.

Lord Judge branded the use of guns a “modern pestilence”, adding: “The law is clear. If you choose to be loyal to a gang member who has committed murder you must, if convicted, expect a substantial prison sentence.”

Yates’s sentence was referred to the Court of Appeal for review as “unduly lenient” by Vera Baird, QC, the Solicitor-General. At a hearing in London, Lord Judge, sitting with Mrs Justice Rafferty and Mr Justice Henriques, agreed that the sentence imposed should have been longer.

Yates was present in the dock of the court for the decision.

Rhys, 11, was shot dead in August 2007 in a Liverpool pub car park as he made his way home from football training. His family were present in the courtroom yesterday.

The Lord Chief Justice said: “A boy was shot dead one summer evening. That tragic death represented the culmination of years of warfare between gangs who armed themselves with guns which they were prepared to use.

“There is no point in us mincing our words. This use of guns is a modern pestilence. It produces fatalities and injuries to innocent victims.”

It also caused “apprehension and fear” to the community as a whole.

Rhys’s parents, Stephen and Melanie Jones, who had described Yates’s original sentence as a “disgrace”, welcomed the increase.

Mrs Jones said outside court that they were “absolutely delighted”. She said a message had been sent to anyone involved in gun crime, or thinking about getting involved, that the sentences handed out would be “tough”.

She added: “I feel relieved because we feel we have been through the mill. It is such an ordeal. You can’t explain what it is like to go through and you think it is never-ending. This will be the last hearing and hopefully we will be able to move on and remember all the good times we had with Rhys.”

Mr Jones said: “We did think the sentence was lenient considering what he had actually done. He had supplied the gun that murdered somebody. We are just really happy that that deterrent is there now.”

He added: “It is the end of the trials and the appeals, but some of those men will be getting out in the not-too-distant future, which doesn’t sit very comfortably with us.”

As well as the firearm charge, Yates, of Croxteth, Liverpool, was convicted of assisting Mercer by helping to dump the gun and his clothing.

Mercer, of Croxteth, was jailed for life and ordered to serve a minimum of 22 years before he can apply for parole, after being convicted of murder in December.

He fired three bullets across a pub car park after targeting rivals who had strayed on to his “turf”.

Rhys was caught in the line of fire and shot in the neck. He died in his mother’s arms a short time later.

The three appeal judges decided yesterday that Yates’s seven years’ detention was inadequate to reflect the seriousness of the combination of the offences, and that the custodial terms should have been consecutive rather than concurrent.

The Solicitor-General said: “The murder of Rhys Jones remains a shocking crime and, for public confidence, the sentences must reflect each player’s criminality.” She said that gang members “must know that the assistance they provide to offenders will meet with punishment”.

Times Recommends

• Times Christmas appeal: Letter from the Editor
• Conferences — what a waste of money
• Schools supremo learns a painful lesson