Coventry Crown Court was told DNA evidence found on a screwdriver, a hat, a security light and a soap tin, as well as a fingerprint on the side of a car, all linked Amos Wilsher to a robbery which led to the death of 88-year-old Josephine Kaye.
Irish-born widow Mrs Kaye died in hospital in 2020, three weeks after suffering a broken leg when she was repeatedly thrown to the floor at her home in Harington Drive, Park Hall, Stoke-on-Trent.
Wilsher, 28, is alleged to have been one of a three-strong gang - including his younger brother, Jason - who killed 87-year-old widower Arthur Gumbley in a raid on his home in Little Aston, between Walsall and Lichfield, in 2017.
Amos Wilsher denies two counts of murder, while Jason Wilsher, aged 22, has pleaded not guilty to Mr Gumbley's murder.
Continuing the Crown's opening speech on Friday, prosecution QC Simon Denison said Mrs Kaye, who was just 4ft 8in, was born and raised in Dublin, where she married and had her first daughter.
Having worked as a clerk in the Rowntree factory in Dublin, she moved to Stoke-on-Trent in 1955 when her husband was offered a job there.
Taking jurors through details of the robbery at her home on February 27 2020, Mr Denison said she lived alone after the death of her husband in the mid-1980s.
At the time she was attacked, the court was told, she she was suffering with a hiatus hernia and had arthritis of the spine.
Mr Denison told the jury: "Mrs Kaye was brutally attacked and robbed in her own home by a lone male. At that time a gas company were carrying out repairs in Harington Drive.
"Earlier on February 27, she thought about one o'clock, Mrs Kaye said that someone she thought was one of the gas men had been to tell her that the gas would be going off, and she said that man had taken the padlock for her gate.
"The gas never did go off that afternoon, and we suggest that that man was the same man who later that evening returned to Mrs Kaye's home and attacked and robbed her, having enabled himself to do so by removing the padlock."
Prosecutors allege Wilsher went back to the property at about 6.30pm, ringing the doorbell after interfering with a security light so he would be in darkness.
Mr Denison went on: "When she did open the door he claimed to be a police officer. He forced her back into her home.
"He ripped the lifeline pendant from her wrist. He demanded to know where the money was, and he threatened her with a long screwdriver.
"He repeatedly threw her to the floor, picked her up and threw her down again as he dragged her through her house. He took about £900 that he found in her purse."
Jurors were told a safe containing £20,000 was taken by the masked intruder, who Mrs Kaye told police was wearing a bobble-type hat with a badge, a dark hooded jacket and red gloves.
Mr Denison said: "Following that attack, Mrs Kaye was admitted to the Royal University Hospital in Stoke-on-Trent.
"Unsurprisingly because of her age, she suffered from a number of pre-existing medical conditions. Her age and her frailty made her extremely vulnerable to the effects of a broken femur and to the consequences of the immobility that the injuries inflicted on her caused.
"She was never well enough to have the operation on her broken leg that she needed, and on March 17 2020 at just after midday, she died.
"Her death was caused by the broken leg and the other injuries that had been inflicted on her."
The jury were then taken through forensic evidence which is said to prove Amos Wilsher's guilt for the murder of Mrs Kaye, including swabs taken from the security light, a soap tin, a fingerprint found on a Honda Civic car, and a DNA sample from black woollen hat found inside the vehicle.
Mr Denison said a complete DNA profile obtained from the inside of the hat matched Amos Wilsher and it was estimated to be "at least a billion times more likely" that the DNA originated from him rather than another individual unrelated to him.
Jurors were also shown CCTV images of the Honda driving into and away from a B&Q store in Meir Park, Stoke-on-Trent, six days before Mrs Kaye was attacked.
Mr Denison told the jury: "That camera captured the grey Honda Civic, we suggest only occupied by its driver, pull into the car park.
"The two items he bought were a long screwdriver and a pair of red gloves."
Both defendants, described in court as being members of a large family from the Traveller community with links to Derbyshire and Leicestershire, also deny charges of conspiracy to rob and wounding with intent relating to the knifepoint robbery of a third pensioner at his home in Creswell, near Bolsover.
The trial continues.