A Polish builder has been convicted of murdering six people on the British Channel Island of Jersey, including his wife and two young children.

The murders by Damian Rzeszowski, 31, took place during a barbecue at the family home in August 2010 after his wife admitted to having had an affair.

He was found guilty Friday at the island's Royal Court of fatally stabbing wife Izabela Rzeszowska, 30; 5-year-old daughter Kinga; 2-year-old son Kacper; father-in-law Marek Gartska, 56; his wife's friend, Marta De La Haye, 34; and her 5-year-old daughter Julia.

Rzeszowski will be sentenced later.

Originally from Nowy Sacz, southern Poland, he moved in 2004 to Jersey, an affluent 45-square-mile British Crown dependency with a population of 90,000, located off the coast of France.