Jennifer Hudson's Ex-Brother-in-Law Convicted of Family Murders
05/11/2012 AT 06:00 PM EDT
The jury in Chicago delivered its verdict against William Balfour, 31, after about 18 hours of deliberations. He faces a maximum penalty of life in prison.
Hudson and her sister Julia said in a statement: "It is our prayer that the Lord will forgive Mr. Balfour of these heinous acts and bring his heart into repentance someday."
Balfour was charged with the murders of Hudson's mother Darnell Donerson, brother Jason Hudson and 7-year-old nephew Julian King in 2008.
Prosecutors alleged Balfour acted out in a jealous rage over what he thought was another man in Julia's life.
Hudson, 30, attended the trial and was the first witness, telling jury through tears that she had warned Julia against marrying Balfour.
"None of us, myself, my mother, or my brother, we did not like how he treated her, and I didn't like how he treated my nephew," Hudson said.
Balfour, who was estranged from Julia at the time of the killings, pleaded not guilty, and his lawyer challenged the forensic evidence in the circumstantial case that lacked DNA evidence or fingerprints.