In western Freiburg, a man stabbed two women on the street.
After the attack by the 63-year-old on Wednesday morning, one of the two women died in the hospital, the police said.
The second victim, a 30-year-old woman, was taken to the hospital with serious injuries.
The attacker was arrested.
A police spokesman said there were many unanswered questions in the case.
It is known that the 63-year-old German knows the 30-year-old woman.
The relationship between the two is still part of the investigation.
The police initially gave no information on the identity of the deceased woman.