A stalker left four victims terrified by bombarding them with messages on Snapchat, Twitter and Facebook.

Kieran Dorian, 20, knew the victims from his schooldays in Dundee and became obsessed with them individually over the course of four years, the city's sheriff court heard.

He went to one woman's door at 3am and stayed till 7am before insisting he walk her to work.

Dorian later posted a "rambling, nonsensical" letter through her door on Christmas Eve.

After spotting another of his victims on a bus he went home and bombarded her with Facebook messages.

A third woman was stalked while she was at work before Dorian sent her 50 Snapchat messages and a video of him scrolling through her Twitter feed.

Fiscal depute Eilidh Robertson told the court: "He made repeated reference to walking to have sex with her and asking to see her in her underwear.

"That was reported to police which sparked an investigation in to his other victims."

In a separate set of charges, the court heard Dorian spat blood at a police officer and threatened to rape her.

Additionally, he faced a charge of sexually assaulting a 13-year-old girl in a fast food restaurant.

Dorian, of Broughty Ferry, Dundee, pleaded guilty on indictment to all charges against him.

Sheriff Alastair Carmichael deferred sentence until January for Dorian to engage with social workers.

He said: "The way you behaved puts you in the territory for a custodial sentence."