ISTANBUL (AP) — A Turkish court on Tuesday acquitted two Turkish men who were charged with aiding and abetting their younger brother in the 2005 shooting death of their sister in Germany.

Hatun Surucu, a 23-year-old divorced mother, was killed by three shots to the head in Berlin by her youngest brother in what prosecutors described as an “honor killing” meant to punish her for her Western lifestyle.

The shooter, her 20-year-old brother, was sentenced to 9 years and 3 months in prison in April 2006. Her two older brothers, Alpaslan and Mutlu Surucu, were acquitted due to lack of evidence.

A German court annulled the acquittals in 2007 but by that time the men had left for Turkey. Turkey, which does not extradite its citizens, agreed to put the brothers on trial in the country.

Prosecutors had demanded that the two be sentenced to between 15 and 20 years in prison each for allegedly helping their brother carry out the killing, according to the state-run Anadolu Agency.

But the court in Istanbul ruled that there was no “sufficient, certain and credibly concrete” evidence against the two and acquitted them.

Fidan Ataselim, head of a rights advocacy group against violence against women, expressed disappointment with the verdict. She said the court rejected a request for her group — “We Will Stop Women’s Murders” — to be a party to the trial and speak on behalf of the victim.

“The suspects had attorneys … their voices were heard,” Ataselim said. “(Hatun) wasn’t able to speak for herself, her voice wasn’t heard.”