The Lubbock District Attorney's office charged Williams with her murder back in 2010, after matching DNA evidence.
After finding Williams guilty, it took jurors less than an hour to decide he should spend the rest of his life in prison.
The defense brought Williams' father, Edward in during the punishment hearing, where Edward said he would like his son to eventually be free, also saying he hopes his son will straighten up and not get in any more trouble.
During closing statements, the prosecution asked the jury to consider if they thought Williams should ever be able to walk free again. They also mentioned Williams' prior record of attempted aggravated sexual assaults, and how Williams was already serving 30 years for a 2003 conviction of aggravated sexual assault.
"It's been a long road, but it was worth every minute," said Sunshine Stanek, Deputy District Attorney.
The Ivey family declined to speak, but did give a written statement saying addressed to Williams, saying Ivey "lived an extremely hard life, she had gone through more than most ever have or ever will. She never had anything easy in her entire life, or even in death."
The statement continues, saying "our family has been under the impression that our mom was thought a homeless woman and we would never find out what monster did this, when in fact that was very far from the truth."
"The family was very pleased their mother was treated with so much respect, and that everyone worked so hard on her behalf," said Stanek.
The statement also expressed gratitude for the work of detectives, police, scientists, and jury members during the last 20 years, and the respect and work that went into the case.
Williams will be eligible for parole in 30 years.