Freiburg police are looking for two additional suspects tied to the rape of an 18-year-old student that saw eight men taken into custody and street protests in the German city.

Authorities on Friday said they found two further sets of DNA traces that do not match any of the others suspects' DNA.

"We have to assume that we are looking at two additional suspects," Bernd Belle from Freiburg's criminal police force said at a news conference. Whether it is likely that even more suspects were involved was "mere speculation," he said.

Suspects from Syria, Germany

Several men are suspected of raping the victim after she had been to a nightclub in Freiburg on October 14. Police said the woman had taken drugs, but that it was unclear whether a drink she had afterward was spiked.

She is currently getting medical and psychological treatment and appears to be in "stable" condition, according to police.

Eight suspects, aged 19 to 29, are currently in custody. Seven of the men are from Syria and one is German.

Police described the main suspect, a 22-year-old from Syria, as a multiple offender. He is also suspected of being involved in another case of sexual assault.

Police also said three of the suspects in custody had posed on the internet with weapons.

"We suspect that they might be affiliated with the YPG or PKK," Belle said, referring to the Kurdish militia and extremist organization respectively.

The rape case sparked protests focusing on the suspected involvement of refugees in the case as well as counterdemonstrations urging caution about focusing on the perpetrators' nationalities.

Extra police presence promised

Freiburg, a university town in the southwest German state of Baden-Württemberg, has been shaken by the rape case and other incidents of violence over the past years.

Freiburg, a popular university and tourist city, has been the site of various violent crimes over the past years

On Friday the state's interior minister, Thomas Strobl, promised in a press conference to send additional police forces to the city.

"My offer is entirely concrete," he said. "We will support Freiburg with extra police personnel."

Strobl said this would allow the city's police officers to focus on invesigating the rape case and at the same time increase Freiburg residents' sense of security.

Stobl had been criticized following the revelation that there was an outstanding arrest warrant for the suspect in the rape case who was a multiple offender.

The conservative politician, a member of Angela Merkel's Christian Democrats (CDU), promised that the state would review how it deals with foreign offenders. While protections afforded to refugees by the Geneva Convention would be observed, Storbl underscored, serious crimes committed by foreigners would lead to the revocation of residency permits.

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With a view to kill: Germany's worst serial killers The horror of Hanover Fritz Haarmann is thought to have sexually assaulted, murdered, mutilated and dismembered at least 24 boys and young men between 1918 and 1924.The full extent of his crimes were revealed after 500 pieces of human bone, some with knife marks, were found by Hanover residents worried about the disappearance of children in the area. Haarmann, who was once a police informant, was beheaded in 1925.

With a view to kill: Germany's worst serial killers The butcher of Berlin Karl Grossmann killed his victims and sold their meat on the black market and at his hotdog stand. After neighbors heard screaming, police burst into his home to find a dead young woman on his bed. It is unclear how many lives Grossmann took, but he is suspected of dismembering 23 women found nearby and up to 100 missing cases in Berlin. He hung himself in 1922 before receiving the death penalty.

With a view to kill: Germany's worst serial killers The terror of Falkenhagen Lake Friedrich Schumann was a locksmith who raped, murdered and stole from 1918 to 1920. After a confrontation with a local forester — whom he shot — Schumann was arrested and charged with the murder of six people and attempted murder of 11 others. He was sentenced to death six times. The night before his execution at aged 28, he admitted to killing 25 people, including his first victim — his cousin.

With a view to kill: Germany's worst serial killers The S-Bahn murderer Paul Ogorzow was convicted for 31 sexual assaults, the murder of eight women and attempted murder of six others in Nazi-era Berlin between 1940 and 1941. Ogorzow worked for the German commuter rail system and would threaten, stab or bludgeon his rape victims before sometimes throwing them off the moving train. He was sentenced to death and beheaded two days later.

With a view to kill: Germany's worst serial killers The death-maker In 1946 and 1947, Rudolf Pleil worked as a border guard in the Harz Mountains and illegally trafficked mostly women from East to West Germany. For a while, he had two accomplices, who would help trap victims. Rudolf Pleil was convicted of killing a salesman and nine women but he claimed to have killed 25 people. Sentenced to life in prison in 1950, Pleil committed suicide eight years later.

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With a view to kill: Germany's worst serial killers Smoking out murder Fritz Honka was notorious for killing at least four women between 1970 and 1975. He strangled prostitutes in his apartment and cut up their corpses. Firefighters found hidden body parts in his apartment after a fire broke out while he was gone. Honka was sentenced to 15 years in a psychiatric institution. After his release in 1993, he lived in a retirement home until his death five years later.

With a view to kill: Germany's worst serial killers The St. Pauli killer Werner Pinzner was a for-hire killer for pimps in Hamburg's red light district. He is thought to have killed between seven and 10 people. Pinzner gained nationwide fame in 1986 when he was brought to the Hamburg police department for interrogation with his wife and lawyer. He suddenly pulled out a gun and shot the investigating prosecutor before turning the gun on his wife and himself.

With a view to kill: Germany's worst serial killers Death by poison A nurse from Cologne, Marianne Nölle killed patients in her care by poisoning them with an antipsychotic drug between 1984 and 1992. Police believe she actually killed 17 people and attempted a further 18 murders, but she was only convicted of killing seven patients. She has never confessed to any of her crimes and since 1993, Nölle has been serving a life sentence.

With a view to kill: Germany's worst serial killers Killer on the roads Volker Eckert was a German trucker who murdered at least nine women, most of them between 2001 and 2006. According to police, there were probably four others. His first victim was a classmate whom he strangled aged 15. Most of his victims were prostitutes he picked up across Europe and he kept trophies like his victims' hair. Eckert hung himself in his cell during his trial in 2007.

With a view to kill: Germany's worst serial killers Angel of death Stephan Letter is a former nurse responsible for the death of at least 29 patients by lethal injection at a Bavarian hospital between 2003 and 2004. Arrested for drug theft, Letter confessed to some of the killings, insisting that he was trying to relieve suffering. He is serving a life sentence and until recently, his acts were described as Germany's worst killing spree since World War II.

With a view to kill: Germany's worst serial killers The killer nurse Keen to impress colleagues with his life-saving skills, Niels Högel would inject patients with cardiovascular medication to induce heart failure or circulatory collapse. He was convicted of killing two people and was jailed for life in 2015. However, after a multi-year probe, investigators now believe the former nurse was responsible for 100 more deaths, making him Germany's most prolific killer.



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