Medical staff at the hospital quickly suspected poisoning, and the
poison control center was alerted even before Anna was formally pronounced dead. Police began investigating immediately, but no food was confiscated from the B. family’s home—despite the strong possibility of food poisoning. In fact, Benedikte B. disposed of all the remaining food in the house shortly after the child’s death. The parents were initially reluctant to allow an autopsy, with the mother strongly opposing it. Eventually, the autopsy was carried out, after which Anna’s body was cremated and buried. Less than two weeks after Anna’s death, the ice cream manufacturer received a blackmail letter demanding 80,000 Deutschmarks and threatening to poison more of its products. The
extortionist, who called himself “Mr. Calva,” contacted the company one more time, but there were no further messages and no money was paid. Authorities considered it unlikely that a financially motivated product extortionist would first poison a product and only later issue a threat, which cast doubt on a connection between the poisoning and the blackmail attempt. Elisabeth F.’s statement that she had eaten the same ice cream herself also seemed to argue against a commercial motive. Roughly eight weeks after Anna’s death, autopsy results confirmed that she had died from ingesting arsenic trioxide, a tasteless and odorless powder. The dose was 20 to 50 times the lethal amount. Because arsenic typically causes nausea within 90 to 120 minutes, the poison must have been administered after 8:00 p.m.—which ruled out food Anna had eaten earlier in the day. The investigation considered whether the arsenic had been in the ice cream or the chocolate sauce, or whether it had been given later, in the tea or herbal medicine. At the time of the crime, both Elisabeth F. and Ernst-Rudolf B. still had keys to their parents’ former pharmacy, which had since been sold. The new owner confirmed that two vials of arsenic were still in the old inventory. An old military field medical kit in the B. family home also contained arsenic, but in quantities deemed harmless. All three adults present that night—Anna’s parents and her aunt—were treated as suspects. Investigators noted that all three appeared emotionally detached and highly controlled. One theory proposed that the poisoning may not have been aimed at Anna herself, but at one of the adults present. However, no clear motive emerged for any of the three. Elisabeth F. eventually became the main focus of the investigation. Her behavior raised suspicions: despite Anna’s deteriorating condition, she left the hospital to take a dog to the vet; at the funeral, she wore heavy makeup and reportedly made inappropriate comments. Investigators also noted that she had been present during both of her parents’ sudden deaths. Additionally, Anna had fallen ill during a visit from her aunt just two months earlier, in November 1992—potentially a failed earlier poisoning attempt. Investigators also found it suspicious that Elisabeth ran the dishwasher the morning after Anna’s death, which included the glass bowl the child had used. This was seen as possible evidence tampering, especially since Elisabeth brought up the dishwasher to her brother just as he informed her of Anna’s death. Despite extensive questioning, Elisabeth F. remained composed. Multiple psychiatric evaluations found no signs of mental illness. Her parents’ cremated remains were later exhumed and tested for arsenic, but no abnormal levels were found, and no charges were filed in connection with their deaths. ==Legal proceedings==