2011/2012 suspected murder of a German man
Christoph Bulwin was a German man who died on May 9, 2012, of complications related to mercury poisoning. The case caught media attention because Bulwin had allegedly been poisoned with a syringe attached to an umbrella by an unidentified perpetrator; the police concluded that the intoxication was probably self-administered. 
Christoph Bulwin.
Christoph Bulwin was 40 years old at the time of the events and was married with two children. The family lived in the Celle area about 50 km (circa 31 miles) from Hanover where he worked as a software engineer and database administrator for "IG Bergbau, Chemie, Energie", the German union of miners, chemical and energy workers.
Attack.
According to Bulwins testimony, on July 15, 2011 at 3.55 pm he was walking from his office to his car on Fischerstraße when he passed a man waiting with an umbrella in his hand. Bulwin perceived the man as suspicious and changed sides of the road. However, the man started following him. When he was passed, Bulwin felt a sting in his left buttock. He approached the man and saw that he held the umbrella with a pointed object attached to its tip. According to the public TV broadcaster ZDF, Bulwin grabbed the umbrella and got hold of a syringe that seemed to have been attached with tape to the umbrella. According to the magazine Focus, the syringe fell out of the umbrella. The unidentified man fled the scene in the direction of Jägerstraße.
Bulwin first suspected an attack with HIV. An ambulance took him to a near hospital where he was checked but no abnormalities were found. Bulwin requested prophylactic medication against HIV but soon stopped taking it due to the strong side effects. Besides that, he did not have any symptoms for the first days after the incident.
Progression of symptoms and death.
About one week after the incident, Bulwin started having symptoms of poisoning such as a rash and severe headache. Later his skin started to peel off. After two months, Bulwin fell into a comatose state. Around the same time, the doctors identified the cause of the symptoms as a type of mercury poisoning: 
However, the diagnosis came too late for an effective therapy. Bulwin would not awake again from his coma and die on May 9, 2012 from an epileptic shock. He was living in a nursing home at the time.
An autopsy was conducted two days after death. The key findings were reported to be:
The death was reported to be due to "refractory status epilepticus which is compatible with brain atrophy potentially resulting from methylmercury intoxication."
Police investigation.
Two days after the attack police put out an appeal for witnesses. The attacker was described as:
During the investigation at the scene several witnesses reported sightings of a man who matched this description. According to the witnesses, this man had waited close to the office building where Bulwin worked and had been seen there days and even weeks before the attack. One witness described an encounter during which the suspect complained about the witness's dog.
In 2013, the police closed the investigation. On August 24, 2022 the case was featured on TV on Aktenzeichen XY... ungelöst where the German criminal police presents unsolved criminal cases which are reenacted. After the broadcast, a police officer in charge of evaluating call-ins during the show reported numerous new clues with two very promising leads. However, no substantial progress has been made as of 2023.
Theories and conflicting accounts.
Due to the lack of a plausible motive the attack was speculated to be a mix-up. A possible connection to the victim's employer, a major trade union, was also speculated. However, neither theory could be substantiated.
The account presented by the media as well as police statements contradicts claims made in the "Forensic Science, Medicine and Pathology" article from 2020. The latter source claims:Police learned of the case after the mercury intoxication was diagnosed, and the investigation revealed a small syringe (typically used for subcutaneous injections, e.g. insulin) containing a fluid with a mercury-thallium bond as well as several beads of metallic mercury bonds at the dashboard (e.g. non-organic mercury, mercury sulphate) of the victim’s car. Furthermore, it turned out that the victim had access to mercury compounds due to his occupation.The mercury Bulwin allegedly had access to was "low temperature thermometers at his workplace [that] contained metallic mercury and 8.5% or 40% thallium." However, "only a small quantity of thallium could have been injected if the man had used the fluid found in his car. It is therefore not likely that an injection of such a preparation led to the patient’s disease". The article stated that the findings made in Bulwin's car "led the police to conclude that the intoxication was most probably self-administered and not the consequence of an attack by a perpetrator. Therefore, the preliminary investigation was terminated." 
In contrast, neither press coverage nor the 2022 case presentation on TV by the criminal police mentioned either the finding of suspicious objects in Bulwin's car or the fact that police suspected the attack to be made up for whatever reason. Moreover, the criminal investigator presenting the case on TV specifically described the substance Bulwin was poisoned with as an "organic mercury compound" that could only have been prepared by an expert in chemistry, thus limiting the circle of potential suspects.
Since police had put out an appeal for witnesses as early as two days after the alleged attack, it is impossible that they would have learned of the case only after the diagnosis (as it was stated in the "Forensic Science, Medicine and Pathology" article).
References.
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