The mother of a 16-year-old girl found dead in a garage last year in south suburban Markham is suing the classified website Backpage.com, saying the company was facilitating sex trafficking of minors.

Yvonne Ambrose filed the suit on Wednesday in Cook County Circuit Court as administrator of the estate of her daughter, Desiree Robinson, according to court documents.

Robinson was found dead Dec. 24, 2016 in the 16200 block of Hamlin Avenue of multiple injuries she suffered in an assault, according to the Cook County medical examiner’s office. Her death was ruled a homicide.

Antonio Rosales, 32, was charged with a count of murder in connection with Robinson’s death, according to the Cook County state’s attorney’s office. He has pleaded not guilty.

Antonio Rosales | Cook County sheriff’s office

Rosales met Robinson through an advertisement selling the teenage girl for sex on Backpage.com, according to the suit. Robinson went missing in November 2016, and ads selling her for sex appeared the next month in the “escort” section of Backpage.com.

The night before she was found dead, “two unknown individuals forced Desiree Robinson into a vehicle and drove her to meet Anthony Rosales,” after Rosales saw advertised on Backpage.com, according to the suit. The unknown individuals received money from Rosales who raped Robinson early Dec. 24.

Later that morning, Rosales contacted the two unknown individuals again about purchasing Rosales for a second time, the suit said. She was brought back to Rosales, who led her inside the garage, where Robinson resisted him. He beat her and cut her throat.

Rosales left the garage and told the waiting individuals who sold her that she would be out soon, the suit said. She was later found dead inside the garage.

The suit seeks more than $350,000 in seven counts against Backpage.com, according to court documents.

Backpage.com facilitated sex trafficking, including the trafficking of minors, by helping to “coach” users posting the advertisements that appeared on its pages, according to the suit. The site helped users “clean up” and “sanitize” posts via manual and automated editing on the advertisements.

The suit also accuses the website of intentionally underreporting instances of child exploitation, using moderators to delete incriminating evidence and profiting from sex trafficking. Backpage did not respond to a request for comment Wednesday night.

The suit also seeks more than $100,000 in damages from Rosales.

Rosales was ordered held without bail at a hearing in Markham in January, according to the Cook County sheriff’s office.