A murderer will be sentenced on Monday for killing two pensioners 20 years ago in a double jeopardy case which made legal history.

Prolific jewel thief Michael Weir, 52, battered veteran Leonard Harris, 78, and mother-of-three Rose Seferian, 83, during two burglaries five weeks apart in 1998, the Old Bailey was told.

Retired cabbie Mr Harris’s widow Gertrude, who also suffered head injuries, died a few years later in a care home.

Michael Weir court case
Gertrude Harris and Leonard Harris (Met Police/PA)

During the attacks, Weir stole a signet ring and gold watch from Mr Harris and ripped diamond rings from Ms Seferian’s fingers, jurors heard.

Connections between the two deaths were not made at the time, after police failed to match Weir’s palm print to one recovered from the Harris home in 1998.

After Weir, of Hackney, north-east London, was found guilty of the murders, Mrs Justice McGowan told jurors they had made legal history.

Prosecutor Tom Little QC said it was believed to be the first double jeopardy case to involve a defendant being found guilty of the same murder twice.

It was also the first time a second murder charge had been added to a double jeopardy case, brought in light of new and compelling evidence following a change in the law in 2005.

Michael Weir court case
Rose Seferian was fatally assaulted in her Kensington home by Michael Weir (Met Police/PA)

Weir had been convicted in 1999 of the murder of Mr Harris, as well as burglary and attacking Mrs Harris on the basis of DNA erroneously kept on the police database.

The original trial judge ruled it was admissible but that decision was overturned by the Court of Appeal in 2000 and Weir’s conviction was quashed.

The Crown Prosecution Service then missed a deadline to appeal to the House of Lords by a day, Mr Little said.

But the Lords later found that, in a similar case to Weir’s, the original decision to admit the DNA was correct.

Weir’s fresh trial was told how he broke into Mr Harris’s flat in East Finchley, north London, leaving him with serious head injuries on January 28 1998. He died in hospital five months later.

An 18-carat gold Zenith watch that Mr Harris had taken from a German soldier during the Second World War and his gold ring were missing.

Three days after the attack, police found a palm print on the bedroom door but missed the match to the defendant at the time, because a comparative print was not the best quality, the court heard.

DNA testing not available in 1998 produced more evidence that Weir was at the crime scene.

On March 5 1998, Ms Seferian was attacked in the three-bedroom flat in Kensington, west London. She died in hospital a month later.

A palm print was recovered from inside the flat on a window frame where Weir broke in but it was not matched to the defendant until 2017, the court heard.

By 2018, the new DNA evidence in the Harris murder had been obtained and the palm prints from both scenes had been matched to the defendant, jurors heard.

Giving evidence, labourer Weir admitted he had a long history of stealing to get money for drugs but denied murder.

Detective Chief Inspector Shaun Fitzgerald from Scotland Yard said: “Weir literally thought he had got away with murder but he now faces a considerable custodial sentence where he will have significant time to reflect on his utterly callous actions towards two completely innocent victims.”