A 52-year-old woman was found dead in her apartment in Berlin.
The police are investigating suspected homicide, a spokesman said on Friday morning.
According to initial findings, a 34-year-old man is said to have attacked the woman and an as yet unknown man in an apartment building on Friday night.
The 52-year-old succumbed to her injuries on the spot.
According to the police spokesman, the scene of the crime is the woman's apartment and parts of the hallway in the large apartment building.
According to the spokesman, the emergency services found a chainsaw and other tools at the crime scene.
The 34-year-old is said to be a neighbor of the woman.
A homicide detective is investigating.
The unknown man was reportedly injured and is currently in hospital treatment.
It is still unclear how badly he was injured.
The 34-year-old suspect was arrested by police shortly after the crime.
He is also currently being treated in hospital for a foot injury.
He is being investigated on suspicion of homicide and attempted homicide, the spokesman said.