Chicago U.S. District Judge Sharon Johnson Coleman sentenced Joseph Hazley to 32 years in prison on Tuesday, telling the court that his actions led directly to the tragic death of 16-year-old Desiree Robinson in 2016.

The teenager was killed by a man in 2016 after being forced into prostitution and held against her will by Hazley.

“He sold my baby. My baby! As if she was a piece of clothing,” said Robinson's mother Yvonne Ambrose at the court in Chicago on Tuesday. The teenager was killed by a man in 2016 after being forced into prostitution and held against her will.

“She was loved by her family, but looked for other sources of love and acceptance, as many teenagers do…Joseph Hazley preyed on that vulnerability,” she added.

Hazley, 35, was convicted in March of trafficking three women, including Robinson, in Illinois, Ohio and Indiana. He posted the women's photos on the now-shuttered Backpage.com, set up meetings and drove them to clients where he waited.

Federal authorities said Robinson was trying to leave Hazley but told friends on Facebook that he was holding her against her will. On Christmas Eve 2016, Hazley drove Robinson to meet a sex client in southern Chicago and waited in the car. When she did not return, he went into the house and found that she had been killed. 

He pulled her cellphone out of her pocket, because it had information that incriminated him, and left the body. He deleted all the photos of her off of his computer and threw out her clothes. He quickly approached another young woman to replace Robinson.

Antonio Rosales, who answered the Backpage ad that night and set up the meeting with Hazley, is facing first degree murder and aggravated sexual abuse charges in Robinson's case. But Robinson's mother said Hazley was just as culpable. 

"Desiree did not deserve this but everyone who was responsible will be held accountable for my daughter's death," Ambrose said through tears in the courtroom on Tuesday.

“I had to identify my baby’s body. I had to sign her death certificate,” she said. “It’s the hardest thing I’ve ever had to do in my life…I would not rest until everyone was held accountable for their part in my baby’s murder.”

Robinson met Charles McFee through Facebook, and he connected her with Hazley after receiving a payment. Last year, he pleaded guilty to sex trafficking charges.

Ambrose has become a fierce advocate for sex trafficking victims and testified in front of Congress last year. She filed a lawsuit against Backpage that accused the website of facilitating sex trafficking and multiple executives from the company are now facing federal charges. She was at the White House last year as President Trump signed an anti-trafficking bill into law.

Gina DuBoni, the family's attorney, said bluntly that "if it wasn't for Backpage, Desiree would still be here with her mom. People like Hazley would never have the chance to exploit children online."

Since her lawsuit, Backpage.com has been shut down.