An abusive man has been jailed for life for murdering a woman he claimed to love after previously killing another partner.

Roger Crossan, known as John, fatally stabbed Moira Gilbertson after consuming a cocktail of drink and drugs.

Crossan, 53, kept the victim's body in his flat for days and left a confession claiming "God will get me."

A judge ordered that Crossan must serve 21 years in prison before he can seek to apply for his release to the parole authorities.

Lady Scott said: "You stabbed your partner in the chest and the nature of the wound was such that her death was inevitable."

The judge pointed out that the 56-year-old victim, who used a walking stick, had restricted mobility and was vulnerable.

Lady Scott said he had previously been violent to Ms Gilbertson when he was convicted of assaulting her to her severe injury and danger of life in 2011 which resulted in a community payback order.

She added: "The seriousness of your conduct is also significantly aggravated by your previous convictions."

As well as being convicted of the manslaughter of a former partner in 1999 in England for which he was jailed for eight years, Crossan has a further conviction for domestic violence against another partner.

The judge told Crossan that she would have jailed him for a minimum term of 23 years but for his guilty plea.

Crossan admitted murdering his victim in October last year at his flat in Dumbiedykes Road, Edinburgh, near the Scottih Parliament, by striking her on the body with a knife.

The offence was aggravated by involving abuse of a partner.

He had originally faced charges including an allegation of attempting to defeat the ends of justice by concealing her body at his flat between October 3 and 14, sending text messages from her phone and claiming she had taken a drugs overdose and theft, but his not guilty pleas to these were accepted.

Advocate depute Bill McVicar said Ms Gilbertson, who had her birthday on October 8, is survived by her mother, brother, sister and adult son.

She was in a relationship with Crossan from 2010.

Mr McVicar said that following the discovery of the victim's body an autopsy was carried out and features were found that were consistent with the death having occurred on October 3 last year after which she was not seen alive.

Ms Gilbertson's brother reported her to the police as a missing person on October 13 after she had not been in touch for a week which was out of character.

The prosecutor said she had failed to keep an appointment with her sister and added: "There was some contact in the form of text messages from her mobile phone number to family members over a few days, but from their form and content it was clear that the messages were not sent by the deceased."

Police attended at Crossan's flat in the early hours of October 14 and found no one appeared to be in. They returned with a joiner and forced entry to the property.

The victim's body was found lying on a couch in the living room covered by a duvet and a search revealed an envelope containing a birthday card with a handwritten note which appeared to be an admission of guilt and an apology to the family, said the prosecutor.

In the note Crossan wrote: "The hurt you feel God will get me."

Police enquiries found that Ms Gilbertson told an acquaintance on October 3 that she was going to see Crossan and she seemed well and happy at the time. They were later seen together on CCTV footage heading in the direction of his flat.

Mr McVicar said: "The accused told acquaintances that Moira Gilbertson was dead but initially said she had died of a drugs overdose somewhere else.

"On one occasion he advised one such acquaintance that he had killed or stabbed the deceased."

Defence counsel Shelagh McCall QC said Crossan had no explanation for killing his victim and added: "He feels remorse for his actions."

She said he had little recollection of events as he had been drinking heavily and taking heroin and prescribed methadone.

The defence counsel said Crossan had a difficult childhood and witnessed domestic violence before being taken into care.