A 41-year-old man has been jailed for 12 years after killing his elderly mum and leaving her body to "rot" in her bedroom for weeks as he continued to live in their home.

Police said Darren Hammond subjected his 81-year-old mother Beryl Hammond to years of abuse and that took advantage of her financially. He reportedly had a history of bullying and violence against his mother and had been using her pension, the court heard.

Darren, who suffered from alcoholism, killed his mother and then left her to rot at the home they shared. He then continued to live his everyday life, including regularly watching pornography online.

Officers discovered the "frail" pensioner's decomposed body in her bedroom on 12 August after neighbours reported smelling something pungent from the house in Sutton Coldfield in Birmingham, West Midlands.

The defendant had "expected the court to find it acceptable that he could live in a small house for many weeks with the decomposing body of his mother without realizing she was dead, checking on her welfare or seeking medical help," said Detective Inspector Caroline Corfield from West Midlands Police Force CID.

A post mortem revealed Beryl had suffered 10 fractured ribs. The court learned that Beryl's remains were in such a bad state that a pathologist was unable to determine the actual cause of death.

Stephen Linehan QC, prosecuting, told the court the jobless defendant had attacked his mother in her bedroom, causing her rib fractures. During the attack, Darren threw his mother to the floor of the room and applied downward pressure across her chest on both sides, Linehan said.

He added: "Given her age and her vulnerability due to ill health, the defendant was well aware that the attack must have carried a high risk of death or really serious injury."

Lineham said that by leaving his mother in her bedroom and shutting the door, Darren must have also realised that it would have hampered any subsequent investigation into her cause of death.

Following a trial at Birmingham Crown Court, a jury found Darren guilty of the manslaughter of his mother between 12 July and 12 August 2017. Darren was acquitted of murder, The Birmingham Mail reported.

While sentencing Darren to 12 years in jail, Justice Julian Knowles said only Darren knew "why and how" he killed his mother.

"She was a frail and elderly lady at the time she died," Knowles said. "She depended on you and you were in a position of trust."

He called the deadly incident a "terrible crime," adding: "You showed not one iota of sympathy or remorse for what you had done."