Gregory Ailles was arrested after the attack in 2008 in which he tied up Grant and Lois Allies in their home and used a metal pipe to beat his grandfather.
He was convicted of unlawful confinement and aggravated assault of his then-76-year-old grandfather and unlawful confinement and assault of his grandmother, who has since died.
Ailles was also found guilty of theft under $5,000 and possession of firearms while he was cleared of three other charges.
He will face a psychiatric assessment before his next court appearance, which is scheduled for Jan. 3.
There’s no word on when sentencing will be scheduled. (CKOR)