A gang of teenagers who attacked a man to steal £300 and then left him to die have been jailed for the “cowardly and vicious” attack. Ringleader Dean Cullen, 19, was jailed for life and must serve a minimum of 20 years after pleading guilty to the murder of David Lucas.

A gang of teenagers who attacked a man to steal £300 and then left him to die have been jailed for the “cowardly and vicious” attack.

Ringleader Dean Cullen, 19, was jailed for life and must serve a minimum of 20 years after pleading guilty to the murder of David Lucas, 31.

Mr Lucas's body was found in the River Wensum near Whitefriars Bridge in Norwich in the early hours of July 2. A post-mortem found he had severe head injuries but may have still been alive when his body was pushed into river after lying stricken for several hours.

Norwich Crown Court heard how Cullen, of Lawson Road, Norwich, stamped on Mr Lucas's head at least five times as he lay motionless in a pool of blood.

His friends Michael Moss, of Spencer Road, Norwich, and Anthony Walker, of Catton Grove Road, both 19 pleaded guilty to robbery and were sentenced to three and a half and three years respectively.

Alan McHugh, 34, of Shipfields, Norwich, was jailed for four years after pleading guilty to perverting the course of justice. He had returned to the scene after hearing of the attack and pushed Mr Lucas, who may still have been breathing, into the river.

In the early hours of July 2 last year, following a drunken night out in the city, Moss and Walker had joined Cullen in attacking Lucas after discovering he had £300 which he had obtained using a stolen credit card.

They had lured Lucas to the side of the river on the pretence they were to carry out a drugs deal. Before the attack Cullen had said: “He is a big man so we will have to keep our wits about us.”

Cullen started the attack by punching Lucas around the head before Walker brought him to the ground with a rugby tackle. Moss then kicked him as Cullen sat on Mr Lucas's stomach and removed the cash from his pocket.

As he fled the scene Moss was heard to say: “I swear I could feel one of his teeth flying out of his mouth.” While the others made off Cullen remained stamping on Lucas's head as he feared he would “grass” on the group.

Speaking after the case Isabel and Brian Lucas, his parents, said they had been devastated by their loss and miss him deeply.

In mitigation Patricia Lynch said Cullen had had a troubled upbringing and had been in and out of care from a young age. He began drinking aged 13 and soon became involved in drugs.

Moss had also had a troubled youth while Walker had only participated in the early stages of the attack. McHugh understood how serious his actions were but had acted out of a “misguided desire to help.”

Cullen is already serving a jail sentence for an offence of grievous bodily harm last year in which he broken his victim's cheekbone with a baton. At the time he was also carrying a machete. All the men involved have criminal histories.

High Court Judge Mr Justice Calvert-Smith said that he had no alternative but to sentence Cullen to life and had decided on the relative strict minimum tariff because of the seriousness of the offence.

“You did not actually intend to kill Mr Lucas but you were entirely reckless as to whether he lived or died,” he added.