(CNN)A 77-year-old British man admitted Monday to killing his 6-year-old great-grandson, who died after being shot with an air rifle.
Albert Grannon, 77, from the village of Sproatley in East Yorkshire in northern England, pleaded guilty to manslaughter and possession of a firearm without a certificate. His grandson, Stanley Metcalf, died after he was shot on July 26, 2018.
Grannon entered his plea at Hull Crown Court and will be sentenced following presentence reports at a later date.
"This was an extremely tragic incident where a 6-year-old boy who had all his life ahead of him had it cut so needlessly short," said Detective Inspector Rebecca Dickinson in a statement. Dickinson led the investigation for Humberside Police.
"It makes it all the more tragic that it was a member of his own family who was ultimately responsible for his untimely death," she said.
An inquest at Hull Coroner's Court heard that the boy died after suffering a pellet gun injury to the abdomen, the Press Association news agency reported.
In a statement given after Stanley's death, his family described him as "vibrant and full of energy."
Dickinson said she was pleased that Grannon admitted his guilt and "faced up to the enormity of his actions."
"Up to now he has shown no real remorse for what happened," she wrote.
Dickinson said that Stanley has a twin sister, Elsie, and the two were "inseparable."
"I can only imagine what she will feel like now and when she reaches any milestones in her life, knowing that she should be sharing them with Stanley," she wrote. "There are no winners in this at all. It has been an extremely upsetting case to investigate for all my officers."
The PA reported that Grannon was granted conditional bail, and sentencing was adjourned until July 2.
Judge Peter Kelson told Grannon: "It is important I make clear to you the mere fact I am ordering a pre-sentence report and renewing your bail should not be taken by you as any indication as to the likely sentence.
"This case, while tragic, is very serious and it's entirely possible that a prison sentence will follow, and you must prepare for that."