MURDERER David Sisman looked at his victim's family and smiled, holding back a laugh, as he entered the dock for sentencing today (Thursday, November 28).

David Sisman, 21, appeared in Newport Crown Court to be sentenced for the murder of Lee Crewe, 36 in Maindee on May 14. 

Sisman stabbed the unarmed Mr Crewe once in the chest in an overhead and downward motion before fleeing the scene and disposing of his clothes and the knife, which has not been recovered.

The blade cut through Lee's ribs and sliced his right lung, causing him to fall to the floor.

Sisman was brought into the courtroom by probation officers. He first looked to his right to see his four present family members, which included his father and his brother.

He then turned his head to his left to see Mr Crewe's family. He callously smirked at his grieving mother and father, Joanne and Dave Crewe, holding back laughter.

Lee's father, who was crying as he entered the courtroom, saw this and called him a "b******."

Both Lee's mother and father say they feel "numb" after the loss of their son, and are struggling mentally, with Joanne "taking anti-depressants for the first time in [her] life."

In a harrowing impact statement read to the court, Joanne recalled the day she stood at the police cordon on Chepstow Road and learned her only son was dead.

"No sentence will ever be long enough," she said.

Lee Crewe, 36, pictured before his death. (Image: Facebook) Sisman was proven guilty following a trial that started in October this year, despite denying the murder charges.

He presented no evidence during the trial, and it was only on the day of his sentencing that he provided the family with an apology, in the form of a letter to the Judge.

Judge Daniel Williams sentenced Sisman to life in prison, with a minimum custodial term of 24 years.

"The court extends our condolences to the family of Mr Crewe, especially to his parents Joanne and Dave," said Judge Williams upon sentencing.

"There was far more to Lee Crewe than the lost, angry man that was presented to the courts during the trial.

"He was a caring, funny and much-loved man, whose mental health struggles must have been as agonising for him to live through as it was for his family to see him go through."

Speaking directly to David Sisman, he said: "You cannot claim sympathy or mitigation from a man under the influence of the drug you were pedalling."

One of Crewe's relatives shouted at Sisman, calling him a "scumbag" as he was led out of the dock.