Cook was killed two and a half years ago while making a desperate call to 911 for help.
Prosecutors Tuesday asked the jury to show Patrick the same mercy he showed Cook by sentencing him to life in prison.
The jury consisting of seven women and five men deliberated for about two hours before sentencing Patrick to 85 years. They also issued a $10,000 fine.
"I'm satisfied with that as long as he can stay in there as long as possible," said Deanna's mother, Vickie Cook.
After the verdict was read, Cook's family spilled out of the court doors with tape placed over their mouths, symbolizing Deanna's voice being silenced in death.
During closing arguments Tuesday, the defense asked jurors to asses a punishment at five years. Patrick's mother said he was a loving son and father to two young children.
Prosecutors told jurors that they had the opportunity to tell people who beat their girlfriends and wives that the system will not tolerate it.
"The cold-blooded brutality of this crime – standing alone – justifies a life sentence," said prosecutor Bree West to the courtroom. "The primary goal is to ensure Deanna Cook is his last victim."
It seems the jurors agreed.
Patrick will be eligible for parole in 30 years.