A court convicted a young Turkish man Thursday of murdering his sister in what prosecutors described as an "honor killing" meant to punish the woman for her Western lifestyle.

Ayhan Surucu, who was 18 at the time of the February 2005 fatal shooting of his sister, Hatun, was sentenced as a juvenile to nine years and three months in prison. Now 20, he had faced a maximum 10-year sentence.

The court acquitted his two older brothers who had also been charged with murder.

Hatun Surucu, a 23-year-old divorced mother, was killed by three shots to her head on a Berlin street.

The case outraged Germans and brought to light the problem of "honor killings" among the nation's 2.6 million Turkish residents. The killings are typically committed by men against female relatives, usually over suspected sexual misconduct, to preserve family honor.

Berlin's top security official, Ehrhart Koerting, said the court case was a step toward cementing a "change in mentality" in the fight against domestic violence.

Hatun Surucu was a German citizen, born and raised in Berlin. In 1998, she was forced to return to Turkey to marry a cousin. A year later, she gave birth to a son in Berlin and refused to return with her husband to Turkey, prosecutors said.

She and her son then moved out of her parents' home against their will and continued her studies, starting an apprenticeship as an electrician, prosecutors said.

Prosecutors argued at the start of the state court trial that her brothers lured her to a bus stop with the intent of killing her because they were ashamed of her Western lifestyle.

During the proceedings, Ayhan Surucu admitted to the murder, saying he regretted the act while insisting his two older brothers were not involved.

"I killed my sister," he said in a statement read out to the court by his attorney.

As the trial concluded, Surucu was still coming to grips with what he had done.

"I wish it hadn't happened," he told the court. "I'm sorry."

Both older brothers, Mutlu Surucu, 26, who has German citizenship, and Alpaslan Surucu, 25, a Turkish citizen like his younger brother, said they had nothing to do with the crime. In acquitting them, the court said the evidence was not strong enough to prove their involvement.