Prison guards discovered the 46-year-old woman had been killed when they checked on them on Sunday afternoon. The 50-year-old prisoner allegedly attacked her and then tried to kill himself. He is now in stable condition at a prison hospital, authorities said.

Justice Minister Roswitha Müller-Piepenkötter offered her “deepest sympathy” to the relatives of the victim, and called for consequences.

“We owe this to the victims and their families,” she said. “And we must seek consequences, so that such an event does not happen again.”

Müller-Piepenkötter, who visited the prison on Sunday, called the situation a “human tragedy.”

Particularly tragic, she said, was that “a woman who wanted to give care and support to a prisoner was killed by his hand.”

At a press conference on Monday afternnon, the police, the public prosecutor’s office and prison officials provided further details of the incident.

The authorities believe the man planned the murder in advance, since they found a broken kitchen knife, a fisher knife and a wrench on the floor of the long-term visitation room.

The victim suffered four stab wounds to the upper parts of her body, a head injury and she also had strangulation marks on her neck, they said.

The killer apparently tried to commit suicide right afterwords by slashing his wrists. He has been incarcerated since 1991 for sexually molesting and murdering a nine-year-old girl at a garden party in Düsseldorf. He was moved to Remscheid prison in 1995. The woman started the date the inmate in 2005.

Coroners believe she didn’t die immediately after the attack, but instead perished on the floor in agony lasting several hours. Her body was found 3:35 pm yesterday and the visit started at around 10:30 am.

The killer worked in the prison library but was considered “not fit for release” at his first parole hearing in 2006, meaning his next chance to be release wasn’t scheduled until 2011.

With reporting by Michael Remmert in Wuppertal.