A young woman has told how a man intent on sexual violence crept behind her late at night and dragged her to the ground in a dark alleyway.

The terrified victim said it felt like she was being abducted when “stealth-like” Mark Roberts covered her mouth to stop her screaming and overpowered her as she walked home in Canterbury.

The 47-year-old attacker's desire to sexually assault his victim was only thwarted when her screaming and struggling woke a quick-thinking neighbour.

Roberts, of Whitstable, followed the woman after a night out in the city centre and waited until she arrived at a remote alleyway at about 11pm before launching his attack.

His victim told how she believed he was attempting to "carry her away" from the quiet track that joins Beaconsfield Road and Beverly Meadow.

Roberts, who suffers from paranoid delusions, denied his actions but was unanimously convicted at the city’s crown court on Wednesday following a trial.

The woman described her horror, recalling how Roberts ran behind her, placed his hand over her mouth and dragged her off the path.

“He said ‘shush, it’s OK',” she told the court.

“I was stuck and there was no way for me to get away.

“[I] feared he would pick me up and take me somewhere, and I didn’t know where.”

She said she “tried to scream” as Roberts frantically covered her mouth “numerous times” before a woman, who was unknown to her, intervened.

The Good Samaritan told the court she flung open her bedroom window after hearing “whimpering and screaming” in the alley.

Fighting back tears, she re-enacted the moment she confronted Roberts, screaming loudly: “Get off her, get off her now - I’m going to call the police.”

Shouting from behind a curtain just metres from the defendant in the dock, she continued: “I had to go and save that girl from this [suspect].”

The resident was settling down to sleep shortly after 11pm when the victim’s pleas for help roused her.

“I heard a whimpering sound, it was a very unusual sound, I couldn’t quite identify it," she said.

“I wondered whether it was an animal, it sounded quite [like an] animal, maybe a fox but it didn’t sound like anything I’d ever heard before.

“Immediately it grabbed my attention and I thought what on earth is that?

“I heard it again and it sounded a little more screamy, so I jumped out of bed and went straight to the window.”

Sounding distressed, she described seeing Roberts with a hand over his victim’s mouth while “stealthily” holding her in a “vice-like grip”, stifling her screams.

“I thought he was going to rape and kill her,” she explained.

Asked how she was feeling, the neighbour said: “Sheer panic, and shock, and a sense of her life being in danger.

“This was incredibly serious and I witnessed a real-life attack.”

She described how, moments after screaming at Roberts, he calmly released the woman and walked towards the city centre.

Meanwhile, the Good Samaritan and others rushed to the victim's aid and alerted 999, with officers soon arresting Roberts in Whitstable.

Psychiatrists told the court Roberts has a diagnosis of persecutory delusional disorder, a form of paranoia where patients believe enemies are mistreating, spying or attempting to harm them or loved ones.

But doctors stressed Roberts was fit to stand trial and had the capacity to form intent - they took the view his rare condition was psychologically unlinked to his criminal actions.

“I thought he was going to rape and kill her..."

The attacker told jurors he believed the woman was linked to a two-decade police conspiracy, spearheaded by a family member, to remotely agitate his breathing patterns.

He argued he ran and headlocked the lone female from behind in a bid to “speak to her”, to then be arrested to confront conspirators within Kent Police.

Roberts said he believes his victim is an actor employed by the authorities to patrol the streets and upset his breathing, ability to digest food and injure his face.

But Bridget Todd, prosecuting, told Roberts he intended to overpower and sexually assault his victim.

“Well if I was going to sexually assault her I’d be wearing a mask,” Roberts replied, adding: “I certainly wouldn’t be harming someone like that.”

Roberts told jurors shoelaces tied into slip-knots found inside his bag were intended as a clothesline for his camp.

And he dismissed the prosecutors’ claims he disposed of his gloves shortly after the attack, arguing they were still inside his bag.

But jurors unanimously convicted Roberts, of no fixed address, of committing an offence with intent to commit a sexual offence and assault occasioning actual bodily harm.

He will be sentenced at the same court in the new year pending psychiatric and probation reports.