Alberto Sanchez Gomez, 28, was nicknamed the ‘cannibal of Las Ventas’, after the Madrid area where he lived with his mother Maria Soledad Gomez.
A jury in Madrid found Sanchez guilty of strangling the 68-year-old after a row.
He cut up her body, put some pieces in Tupperware boxes and spent the next two weeks eating parts of his victim or feeding parts to his pet dog.
Sanchez cooked some parts or ate others raw, the court heard.
Sanchez will be sentenced in the next few days but prosecutors have asked for the former waiter to be jailed for 15 years and five months for homicide and the desecration of a human corpse.
When he was arrested in February 2019, Sanchez told police that he had been eating his mum “bit by bit” with his pet dog, the court heard.
“Yes, myself and my dog have been eating her bit by bit,” he was reported to have told officers.
Police found Mrs Soledad’s remains in Tupperware containers in their fridge and bones in drawers around the family home.
Her head, hands and heart were found on her bed.
Spanish media reports said her body had been cut up into more than 1,000 pieces.
A worried friend of Mrs Soledad raised the alarm, telling authorities she had not been for over a month.
During the trial at Madrid’s Audiencia Provincial, prosecutors said Sanchez used a carpenter’s saw and two kitchen knives to cut up his mother’s body.
Sanchez told the court that he heard ‘hidden messages’ when he watched television and voices telling to kill his mother.
He said the voices were those of neighbours, acquaintances and celebrities.
However, he insisted he could not remember cutting up his mother or eating her remains.
During his address to the court, Sanchez said: “ ‘I’m very repentant. I suffer anxiety from the moment I wake up.
‘I think of my mother and I’m absolutely heartbroken.”
Jurors heard that Sanchez, who started consuming drugs and alcohol from age 13, had been arrested 12 times for mistreating his mum before he finally killed her.
A police officer who gave evidence during the trial said: “’He also said he had eaten parts of her body, some cooked and some raw, and had given some pieces to the dog.”
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