A quick-thinking guard saved a witness from an attacker who leapt at him from the dock.

Alan Wood, of Flagg Court, South Shields, was facing trial atNewcastle Crown Court yesterday for maiming Lee Costella.

When Mr Costella confirmed it was Wood who stabbed him, the 20-year-old vaulted from the dock of the court and charged for the witness box, screaming: "Watch. I'm going to do you."

Dock officer Andre Fisher grabbed Wood by the scruff of the neck and hauled him, one- handed, from the courtroom floor and back into the dock.

Mr Fisher then restrained his arms and pinned him to the ground with his knees as Wood continued to shout at the witness.

Four guards then cuffed and led Wood from the dock to the cells.

When he returned to court, Wood changed his plea and admitted wounding with intent to cause grievous bodily harm.

He was warned that he could be facing a life sentence behind bars.

Earlier, Alec Burns, prosecuting, said that the stabbing occurred on June 13, in Devonshire Street, South Shields. He said: "Wood shouted something about a stolen top and took a few swipes at him with the knife.

"He then threw a few punches then aimed a few more swipes, swinging the knife in slashing movements. He inflicted a serious wound to Mr Costella's head - a 6in scar which required 18 stitches and other damage."

Judge John Evans, praising the court officer for his bravery, said: "The response of Mr Fisher was commendable.

"I would like to express my thanks to him and to the court administration.

Sentencing was adjourned for six weeks for reports.