On 12th birthday, dad first raped her, court told

KOBLENZ, Germany - The father first raped his daughter on her 12th birthday, after the other children had left her party, prosecutors said as a stomach-turning incest case opened yesterday in western Germany.

The man, identified only as Detlef S. in line with privacy rules, sat stone-faced at the state court in Koblenz as Judge Winfried Hedge read aloud a letter written by his daughter, now 18.

"You made my life a living hell," she wrote.

Detlef S., 48, is charged with 350 counts of sexual abuse - tormenting his daughter, stepdaughter and stepson for more than 20 years. He also faces 35 other sexual counts for allegedly forcing the two girls to have sex with other men for money. He faces up to 15 years in prison if found guilty.

Prosecutors said before the trial that DNA samples confirmed that Detlef S. had fathered his stepdaughter's seven children. An eighth child died before DNA tests could be done.

Prosecutors told the court that Detlef S. first began molesting his daughter when she was 9, raped her when she turned 12 and regularly sexually assaulted her from then on, the DAPD news agency reported.

He had already been abusing his twin stepchildren, who are now 28, starting in 1987 when they were only 4 years old, until 2010, according to the indictment.

After the stepdaughter's testimony, the judge said prosecutors are also investigating whether the defendant assaulted a daughter he had with his stepdaughter in 2004.

Bjoern B., the stepson, left the trial after about an hour, appearing shaken. "I wanted to give my sister strength to go on with this," he said. "We are in this together, and together we are trying to have the strength to live through this. It would make no sense to do this alone."

Detlef S., a truck driver who lived in the small town of Fluterschen, near Bonn, did not address the court. He has been in custody since August, after his daughter came forward to authorities.

The trial resumes today.