Mother and son were killed and two policemen wounded during a raid in the German municipality of Kirchheim an der Weinstrasse on Friday.
Police were deployed in Kirchheim around 8.30 a.m. after a local resident phoned in to report that her 25-year-old son attacked her.
The woman said the man was suffering from drug abuse and had a mental condition.
The man and his 59-year-old mother were killed during the raid, Frankenthal Chief Prosecutor Hubert Strober said.
A 31-year-old female police officer and her 56-year-old male colleague were also wounded during the operation.
Witnesses say they heard several shots fired at the scene.
Elite Special Deployment Commando (SEK) police unit was deployed in the neighbourhood, and several helicopters were also flown in.