An “abhorrent” killer who murdered and raped an Islington teenager almost 50 years ago has been jailed.

In 1975, Dennis McGrory, then aged 28, sexually assaulted, stabbed and strangled his 15-year-old niece Jackie Montgomery at her home in Offord Road.

McGrory, now 75, was sentenced to a minimum term of 25 years and 126 days at Huntingdon Crown Court today (January 13).

During sentencing, Mr Justice Bryan described the killer’s crimes as “abhorrent” and “hideous” and said that McGrory “put Jackie through a horrific, violent and sustained ordeal”.

He said: “How any man could inflict such sexual violence on a 15-year-old child that had done them no harm beggars belief."

He added that due to his age, McGrory would “in all probability” die in prison.

Islington Gazette: Jackie MontgomeryJackie Montgomery (Image: Met Police)

McGrory was cleared of murder in 1976. But decades later, after swabs from Jackie’s body produced a one-in-a-billion DNA match and a 2003 change in the law on double jeopardy, his case was referred to the Court of Appeal.

The retrial, which was scheduled for March last year at the Old Bailey, was halted when the defendant, of Cherry Road, Newport Pagnell, Milton Keynes, fell ill.

He appeared for his retrial at Huntingdon Crown Court by video-link and was found guilty of rape and murder last month.

Jurors were told that McGrory attended Jackie’s address looking for her aunt, who had recently ended their relationship and moved to Manchester in an attempt to get away from him.

Police said Jackie’s aunt was not at the address when McGrory turned up that night, and he likely then took his anger and frustration out on the teenager.

Jackie’s body was discovered on June 2 by her father and a post-mortem revealed she had been stabbed several times, strangled with the flex of an iron, and received blunt force trauma injuries to her face.

At the hearing on Friday, Kathy Montgomery, Jackie’s sister, said: “A violent man who had been living within our family murdered my sister.

Islington Gazette: Kathy (left) and Lisa (right), sisters of Jackie Montgomery speak to the media outside Huntingdon Crown CourtKathy (left) and Lisa (right), sisters of Jackie Montgomery speak to the media outside Huntingdon Crown Court (Image: PA)

“He has been able to live his life. I find that unbearable when my sister didn’t even reach her 16th birthday. His actions caused trauma to so many people and there were no consequences for him.

“The investigation of the last few years has meant revisiting memories of the murder which has caused pain and stress for me and my family and I am relieved that we finally have justice for Jackie.”