The 35 year old Brillion man was convicted of killing his mother, 52-year-old Kathleen Remter, who was discovered floating in the Fox River near Wrightstown in July of 2012.
Prosecutors say Rosenthal shot his mother in the back of the head while the two were at Rapid Croche Park fishing. They say his motive might have been a half million dollar life insurance policy that he stood to inherit.
Rosenthal took the stand Friday to say that he was innocent, and that when he left his mother on the banks of the dam, she was still fishing.
Rosenthal faces a mandatory sentence of life in prison, but a judge may decide that he's eligible for parole after 30 years.