Arthur Gatter

Arthur Gatter (1940 – 12 December 1990), nicknamed The Hammer-Killer of Frankfurt, was a German serial killer.

Life
Arthur Gatter was an electrician by profession who lived in Australia for a while. After returning to Germany, he worked on assembly. Since the 1980s, he was no longer able to work and trashed his apartment in Wilhelm-Leuschner-Straße. It is believed that his schizophrenia was already greatly advanced at this time. Even in his next residence in Bornheim, he behaved suspiciously. Partly he had to be examined in a clinic for psychiatry and psychotherapy in Haina.

Murders
The murders occurred from 1 February to 22 May 1990, in the outskirts of Frankfurt. Frankfurt at the time had around 2,400 homeless staying in the city and especially in the greener areas.


 * 2 February 1990: a crime scene was found in Weißfrauenstraße. A security guard found the homeless 43-year-old Hans-Peter "Peterchen" S. at 5:00 AM.
 * 7 February 1990: Another victim, 22-year-old Kurt Helmut H. was found with fatal head injuries. He was not a homeless person, therefore initially no connection to the first victim was established.
 * 2 April 1990: At the bus stop at Rechneigrabenstraße. At 5:40, homeless man Helmut R. was found with severe head injuries which led to his violent death.
 * 3 April 1990: Two victims were killed near the Eschenheimer plant.
 * 9 April 1990: Helmut R. was murdered in Ostzeil.
 * 4 May 1990: 46-year-old Hans-Peter M.'s bloody corpse was found around 7:30.
 * 5 May 1990: 60-year-old Engelbert G. and 42-year-old Nicola Z. died about 50 metres apart. A crime scene photo with a bloodstained park bench visualised the brutality of the act. This meant that three homeless people had been murdered within 24 hours.
 * 20 May 1990: Brazilian native Anderson S. followed a man into a bush, supposedly to have sex with him. However, he was instead stabbed but managed to survive. The badly-injured man fled and collapsed on a park bench, where he was subsequently killed by the murderer.
 * 22 May 1990: Heinrich O. became the Hammer-Killer's last victim. A local resident had witnessed the incident and alerted the police. Only 12 minutes after the murder, a suspect was arrested.

Investigation
The police reacted to the deaths on 3 April and founded the special operation "Berber" under Commissioner Karlheinz Wagner, and measures were taken. For example, dolls were draped as potential victims on park benches and plainclothed officers were to lure the offender as "decoys". The police tried with surveillance technology (including stealth cameras in bird houses) to catch the culprit red-handed. However, the diffused parking lights and the inadequate camera technology were not enough to attract investigation-relevant images. Even a survey of dry-cleaning companies on whether blood-stained clothing has been delivered provided no results. In the homeless scene, the fear was reversed and the city put up additional shelters and left the subway stops open overnight, so that as few people as possible had to sleep on park benches.

On 11 April 1990, a homeless man said he saw a man approach a sleeping person with a blunt object. After a facial composite was made, a suspect was arrested in Gallus, but had to be released due to lack of evidence.

On 22 May 1990, Arthur Gatter was arrested in connection to the hammer murders. As the supposed murder weapon a metalwork hammer was secured, which he carried hidden in a plastic bag in the armpit. Through this instrument, the typical impression fractures or perforated structures in the skull came about, as determined in forensic medicine. He systematically searched for victims on park benches and surprised them in their sleep. He watched them for a while, until he was sure he could do his job safely. For sneaking purposes, he wore low-noise rubber gloves. He hit with so much force that the blood splashed meter-wide.

A psychiatric report which was made at the time attested him an insanity defense. Before he could be taken to court, on 12 December 1990, Gatter hanged himself with a gauze bandage.