A mother in Italy has been sentenced to 30 years in prison for killing her 8-year-old son with electric cables, but the motive is almost as shocking as the crime: her son had caught her having sex with his paternal grandfather.

Veronica Panarello, 28, was sentenced Monday in an Italian court after having been found guilty of strangling her son, Loris Stival, 8, with electrical cables and dumping his body in a gully in their hometown of Santa Croce in Sicily in November 2014, according to reports from Italian media. Panarello admitted to the crime after first trying to pin Stival's disappearance on a kidnapping. She later confessed that the real reason Stival was murdered was that the young boy had caught her in the midst of a salacious affair with the boy's grandfather, her father-in-law.

In 2014, Panarello told police she had taken Stival to school the day of the incident and that he had disappeared before she picked him up at the end of the day. But Italian police began to suspect the mother was lying after the school's security footage revealed that Stival had, in fact, left school in his mother's care. When confronted with the footage, Panarello confessed to police that later that day she strangled the boy to death with electric cables before deciding to stage his disappearance.

However, Panarello's confession came with a bombshell revelation. She said the reason she killed her son was to conceal her affair with her husband’s father, Andrea Stival. The pair had apparently been carrying on an ongoing sexual relationship. She told the court that Andrea Stival had helped to plot the murder.

Stival is being investigated as an accessory to murder but has not been charged. He has denied the claim and is threatening to sue his daughter-in-law for slander, according to local media reports.

Panarello was sentenced to 30 years in prison on Monday. Her husband has filed for divorce.