A judge expressed “grave concerns” over the freedom enjoyed by life prisoner Lee Cyrus as he was found guilty of a string of attacks on Hampstead Heath following his escape from an open prison.

Judge Deborah Taylor said the court “would wish to hear more” about the supervision of Cyrus at sentencing next week after he was convicted of 11 violent and sexual offences at Southwark Crown Court on Tuesday.

The 48-year-old had escaped from North Sea Camp open prison in Boston, Lincolnshire, before carrying out his spree of violence and intimidation in and around Hampstead Heath.

He was already serving a life sentence for a savage attack on a 92-year-old widow when he wandered out of the prison on October 9 last year.

On Tuesday, as she adjourned for sentencing, Judge Deborah Taylor said: “It is a matter of grave concern the level of supervision in the community which was given to the defendant prior to his parole board hearing in this case.

“It’s something the court would wish to hear more about prior to the sentencing hearing.”

Cyrus had a lengthy history of violent and sexual convictions, which also included 14 months for having sex with a 13-year-old after spiking her drink in 1999, seven years in 1984 for robbing and beating a 79-year-old woman, and six years in 2002 for slashing a couple with a screwdriver.

Prior to his escape, Cyrus had been living in lodgings close to the open prison with others who were being prepared for release in the community, and working in the nearby cemetery.

The only restriction was a requirement that he sign himself in and out when leaving.

He failed to return to the prison lodgings on October 9 before boarding a London-bound coach on October 20.

On Tuesday, Cyrus was convicted of five counts of exposure, wounding with intent, unlawful wounding, affray, aggravated burglary, robbery and burglary. He was cleared of a further charge of exposure and attempted rape.

During his six-week crime spree last autumn, Cyrus often appeared from the trees with his face covered to “flash” his genitalia at female walkers. As the weeks wore on the violence escalated.

He attacked a 63-year-old on her doorstep in Hampstead, threatened an 81-year-old with a knife at her home in Golders Green, and hit a 61-year-old woman with a 4ft metal bar – an attack that was captured in chilling CCTV footage.

During the trial he insisted police had simply “got the wrong man”.

But he was convicted a year and a day after being captured by Camden Police on December 2 last year, following an exposure incident in Highgate.

Prosecutor Christopher Amis told the jury: “Lee Cyrus, on a number of occasions while armed with a knife and wearing a black balaclava, stalked and terrorised female members of the public walking on and living in Hampstead Heath.

“On most occasions he was careful to disguise his face as he prowled wooded and secluded areas.

“His offences increased in seriousness.

“They graduated to brutal attacks on elderly females, who he targeted because they were alone in their own homes.”

Cyrus, of no fixed address, will be sentenced on Friday next week.