A 23-year-old man from the USA killed and then beheaded his 64-year-old grandmother in the apartment where they lived.

The gruesome murder was revealed last Thursday when police were called to a homicide in a San Francisco apartment.

When the police entered the apartment they found the decapitated body of 64-year-old Elvia Lopez-Arroyo.

According to the BBC, suspicions were directed from the first moment to her 23-year-old grandson Luis Gustavo Arroyo-Lopez who lived with his 63-year-old grandmother and he was on probation after his recent release from prison of assault with a weapon and possession of a weapon.

He left the apartment holding his grandmother’s head

The 23-year-old after attacking and killing his grandmother, then decapitated her and finally he left the apartment with the woman’s head in his hands.

It is noted that several weapons were found in the family’s home. The 23-year-old was arrested Saturday morning when he was spotted by a San Francisco police officer on a tip.

The woman’s head was found a few hours after the 23-year-old was arrested on a river bank.

The motive of the 23-year-old is not yet known.