A SEX attacker faces a possible life sentence for raping a mum who was found dead hours later.

Lars Pedersen, 37, preyed on Alison McAllister next to the Forth and Clyde Canal, near Glasgow's Maryhill in March 2018.

The 56-year-old had been grieving at the time as it was the day after the birthday of her late partner, who passed away suddenly following ten years together.

Pedersen left Alison lying on the canal path to go to a friend's home.

Her worried family went on to report her missing to the police.

The predator later returned to the scene and discovered the care home worker's lifeless body still there.

On Tuesday, Pedersen appeared at the High Court in Glasgow and admitted raping Ms McAllister on March 19 or 20, 2018.

He was not charged in connection with her death.

However, the hearing was told Pedersen was previously charged with raping another woman in England around 2012, but she also died before the matter reached court.

A judge has called for background reports to decide whether an Order for Lifelong Restriction should be imposed on Pedersen.

The case was adjourned until July.

READ MORE: Man charged with raping Glasgow mum Alison McAllister

Ms McAllister had lived with her mother, who she looked after at her home in Glasgow's Summerston.

The mum had been in a relationship with her "childhood sweetheart", but he died suddenly in January 2009.

According to relatives, Ms McAllister "changed overnight" as she struggled to cope with what happened.

This got worse around the anniversary of the death and on her late partner's birthday on March 18.

On the evening of the rape, Ms McAllister ended up at the Forth and Clyde Canal having told her daughter she was going to the supermarket.

It was there she was confronted by Pedersen as she sat there.

Ms McAllister told him to "go away", but the sex attacker urged her to go with him.

Prosecutor Owen Mullan said: "Pedersen thought she was drunk, upset and visibly crying.

"He told her to 'relax' and 'calm down', but she did not listen to him and started to become annoyed with him."

Pedersen went on to rape the vulnerable woman.

After the attack, Pedersen claimed Ms McAllister fell asleep before he got her dressed and put her hood up to "keep her warm for the night".

Ms McAllister’s concerned family meantime had been trying to contact her after she failed to return home.

They eventually reported her missing around 11pm on March 19, 2018.

The next afternoon, Pedersen, who had been living with a friend in the local area, went back to the canal path.

Mr Mullan said: "According to him, he found her dead. He checked for a pulse and then returned to the canal bank where he summoned help."

Pedersen initially told police he had discovered the body, but failed to mention having earlier been with Ms McAllister.

After then being arrested for rape weeks later, Pedersen went on to give a bizarre account to detectives.

This included claims he was "attracted" to Ms McAllister and that he had sex with her because they were apparently having a "good time" at the canal.

One officer put to him: "Did you ask her if she was happy to have sex?"

Pedersen responded: "Yeah."

The detective asked: "What did she say?"

He replied: "She said she was not happy. She started complaining and things like that."

Ms McAllister’s cause of death was not stated in court this week.

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Pedersen first appeared in the dock for the crime in May 2018.

He has been on remand in prison since then. 

His QC said the case had an "extremely protracted and complex history".

Brian McConnachie, defending, added Pedersen had been seen by a string of medical experts who had "flip flopped" on whether the rapist was fit to stand trial.

Lord Doherty adjourned the case until July 25 in Edinburgh.

As Pedersen was lead back to the cells, a relative of Ms McAllister’s yelled he wanted the attacker to "rot in his cell".