The letter said that F. could suffer from a mental illness that had not been diagnosed, Meyer continued. He is therefore particularly angry at the followers of religions, especially Jehovah's Witnesses. F. was a member of the community there himself until a year and a half ago.

The anonymous letter writer wanted F. to be checked for compliance with gun regulations, Meyer said. The 35-year-old was legally in possession of a semi-automatic pistol as a marksman. At the beginning of February, police officers from the weapons authority visited F. at home in Hamburg-Altona unannounced.

Meyer said he was cooperative. The officials had checked compliance with the firearms regulations and, apart from the fact that a projectile had been outside the safe, had no complaints. There were also no indications of F.'s mental illness.

After that, the legal options for police measures had been exhausted, said the police chief. He announced that he wanted to take another critical look at the processes.