Kempten, Germany - An American man accused of raping and killing a fellow US tourist near Bavaria's famed Neuschwanstein castle last year made a wide-ranging confession on the first day of his trial Monday.

Troy Philipp B. faces several charges including one count of murder over the death of the 21-year-old woman. He also stands accused of the attempted murder of the victim's friend, also an American citizen.

"The accused committed the incomprehensible act," his lawyer Philip Mueller told the district court in the southern town of Kempten.

The two women, then 21 and 22 years old, had been hiking in the Neuschwanstein area in June last year when they met B., who offered to take them to a viewpoint, investigators said.

At a secluded spot, the man, then 30, allegedly pushed the 21-year-old woman to the ground and proceeded to rape and strangle her.

Her friend intervened, leading to a scuffle in which the accused allegedly pushed the 22-year-old off a steep slope.

The accused then continued his sexual assault of the 21-year-old woman, strangling her with a belt while filming the act.

Interrupted by hikers who stumbled on the crime, he pushed the rape victim down the same slope while she was unconscious.

When mountain rescue workers found the two women, the 22-year-old was injured but able to talk.

The rape victim was seriously injured and taken by helicopter to hospital, where she died later that night from her injuries.

B.'s lawyer said the accused had not planned the attack in advance.

"He was aware that the victim could die without help, yet he still left her behind," Mueller told the court.

His client was "deeply ashamed" about his actions and wished to apologize to the victim's family, the lawyer added.

B., who hails from Michigan, spoke only to confirm the accuracy of his lawyer's statement to the court.

He is not expected to make any further comments during the trial, scheduled to run until March 13.

Germany's top-selling daily Bild reported that the rescue operation and his subsequent arrest took place in front of hundreds of tourists.

Built in the 19th century by King Ludwig II, Neuschwanstein castle is one of the most visited sites in Germany, attracting over a million visitors a year.

B. faces up to life in prison if convicted.

B. on Monday also confessed to possession of child pornography, which investigators uncovered as part of their probe into the attack.