Case Study: Computer Forensics in an Attempted Homicide Case

Case Study: Computer Forensics in an Attempted Homicide Case
By Stan Mitchell,
Forensics Lab Manager

In early 2002, a female was hospitalized due to weight loss, hair loss, and many other ailments. Initial tests revealed that the woman had an extraordinarily high level of Thallium (a highly toxic chemical that has been used in rodent and insect poisons) in her system. While hospitalized, the level of thallium in the woman’s bloodstream increased. Suspicious that family members or visitors could be intentionally poisoning the woman, the hospital notified Law Enforcement.

Hospital personnel, as well as Police, began monitoring the patient’s visitors, and thallium levels were checked after visits. It was discovered that after visits with the family, the patient’s level of thallium reflected an increase. Based on this information, Police obtained a search warrant for the family home. The search warrant detailed the search for any toxic chemicals, specifically Thallium, as well as documentation of chemical purchases (hard copy or on computers). The search of the home recovered no toxic chemicals, but three computers belonging to the family were seized for forensic analysis.

Forensic analysis of the three computers included conducting keyword searches such as “thallium”, “poison”, and so on. Deleted files were recovered that revealed that searches had been conducted on the Internet in late 2001 for “Thallium Poisoning” and “Thallium Poisoning Cases”, well before the victim had been hospitalized. Additionally, a document recovered on the husband’s computer contained a chemical price list. The document was titled “Springfield”, so an additional keyword search for the word “Springfield” was conducted. This search recovered deleted files that reflected that the user of the computer visited a website that sells chemicals and scientific products.

Armed with this information from the Computer Forensic Analysis, the Police focused their investigation on the victim’s husband. Investigation into the husband’s background revealed that he had a girlfriend in Jackson, Mississippi. The girlfriend was interviewed, and it was discovered that she had been hospitalized a few years earlier due to arsenic poisoning. With the focus of the investigation now on the husband, he was interviewed and subsequently arrested for the poisoning of his wife, as well as his girlfriend in Jackson, Mississippi.