BERLIN — An Afghan migrant went on trial in southwestern Germany on Tuesday on charges he raped and murdered a 19-year-old medical student, a highly publicized case that fueled a nationwide debate about the country’s immigration policies.

About a dozen supporters of the anti-immigrant Alternative for Germany party, and about 50 counter-protesters, demonstrated outside the Freiburg state court as the trial of Hussein K. began, the dpa news agency reported.

K., whose last name hasn’t been released in line with German privacy laws, was one of 890,000 migrants who entered Germany in 2015. His true age remains unclear and is a question being addressed during the trial.

He told the court as the proceedings began that he had informed authorities when he entered Germany he was 16, but was actually 18, and is now 19. Prosecutors maintain he was 22 at the time of the October 2016 crime, which could significantly affect his sentence if he’s found guilty.

The victim, Maria L., vanished almost 11 months ago on her way home from a party in Freiburg.

According to the indictment, K. allegedly ambushed her just before 3 a.m., pulling her from her bicycle, strangling her, biting her and raping her. Prosecutors allege he then put the unconscious young woman into a river and she drowned.

The body was later found in the river. Authorities said K. was linked to the crime through DNA evidence and video footage from near the scene.

No pleas are entered in the German trial system, but K.’s attorney said as the proceedings opened that he planned to make a statement about the crime itself.

In addition to fueling anti-migrant anger, the case highlighted communication failures among European countries after it was revealed that Greece didn’t inform other countries that K. was in violation of his probation there following his early release for attempted murder.

The trial is scheduled to continue through Sept. 11.