In January, it was revealed that police were investigating a pedophile ring in the southwestern German town of Staufen outside of Freiburg, where a 9-year-old boy had been abused for two years by his mother and her partner.

The male partner also posted pornographic material of the boy on the so-called darknet — websites that can only be accessed using special software — and offered to have people sexually assault the boy in exchange for money with the help of his mother.

It took three hours for prosecutors on Monday to read out the over 100-page indictment in court against the boy's mother and her partner, the two main suspects. The two face charges of rape, forced prostitution and other offenses in over 50 instances.

The case shocked people across Germany, including police who described it as one of the worst child sex abuse cases they've ever investigated.

Red flags from the start

Although there are several suspects who are facing charges over their involvement in the pedophile ring, prosecutors said Berrin T., the 48-year-old mother of the boy, and Christian L., the woman's 39-year-old partner, were the main perpetrators.

But there were warning signs prior to the abuse in Staufen. According to the German newspaper Süddeutsche Zeitung, Christian L. was handed a one-year suspended sentence in 2005 for having child pornography on his computer and his phone. A few years later in 2010, Christian L. was sentenced to over four years in prison for sexually abusing a 13-year-old girl.

Both times he was ordered to take part in therapy and said he was willing to do so.

Upon his release from prison in 2014, he was considered to have a high risk of relapse and was barred from having contact with children or youths — only under the supervision of the child's parent or legal guardian.

Abuse begins

At the beginning of 2015, Christian L. and Berrin T. became a couple and he began sexually abusing her son shortly thereafter, according to prosecutors.

Christian L.'s petition to have his child contact ban lifted was denied in August 2016. Despite this, he moved in with Berrin T. and her son a few weeks later in the town of Staufen.

During this time, prosecutors said that Berrin T. also allowed Christian L. to sexually abuse a three-year-old, mentally handicapped girl who was temporarily under Berrin T.'s care. The woman also filmed the encounters.

Christian L. also continued to abuse Berrin T.'s son. Besides posting pornographic images of the boy on the darknet, the couple also decided to start offering the boy up to darknet users based in Germany and other European countries to physically abuse, assault and rape the boy in exchange for money.

According to prosecutors, Berrin T. would often take part in the sexual assaults by driving her son to meet with the men, restraining him and forcing him to take part by threatening him that he would end up in foster care if he didn't comply. She also allegedly took part in the sexual assaults herself.

Misjudgments from local authorities

By March 2017, the local youth welfare office stepped in and took custody of the boy after a police detective told the office that Christian L. was living in the apartment with him.

Berrin T. objected to the decision to remove the boy, eventually winning her case in court. Her son was sent back home within weeks.

She was ordered, however, to not allow Christian L. to enter the apartment again. He was also barred from having contact with her son, even when Berrin T. was around. The couple ignored the order and Christian L. continued to have contact with the boy.

Both the local courts and the youth welfare office traded blame after the horrific situation came to light, with the youth welfare office maintaining that the boy did not show signs of abuse at the time.

Pedophilia ring busted

In September 2017, there was a break in the case. An anonymous tip was sent to the Federal Criminal Police Office, saying that the 9-year-old boy had been sexually abused.

Investigators then launched a massive investigation into the couple, eventually arresting both Christian L. and Berrin T. 

In the weeks that followed, six others were arrested in connection with the pedophile ring, making a total eight defendants. All are being tried separately.

Several of the men who abused the boy have already appeared in court. A 41-year-old German man was sentenced to 10 years in prison for rape and severe sexual abuse in mid-April.

A 50-year-old soldier with the German army was sentenced to eight years in May for raping the boy twice as well as filming and circulating the pornographic material online.

A third man, a 37-year-old Swiss citizen, confessed in early June to sexually assaulting the boy on three occasions, paying a total of €50 ($59) as well as giving the boy a cheeseburger and a used computer.

On Monday, the trial began for a 44-year-old German man who made an offer to Christian L. on the darknet, asking if he could sexually assault the boy and then kill him.

As more gruesome details of the two-year-long abuse of the Staufen boy have been made public, the case has sparked outrage — not only at those who took part in the years-long abuse of the boy, but also at the structures that failed to protect him.