The Tylenol Terrorist

Following Lewis' arrest in December 1982, law enforcement agencies working on the case were unable to find any new suspects related to the murders. The team that was initially established to work on the case dwindled along with the hopes of catching the killer. What remained was a roughly drawn criminal profile and partial fingerprints taken from some of the bottles, which remained unmatched. 

The profile of the Tylenol terrorist had been widely disputed throughout the investigation. According to an article by Dawn Hobbs about profiling, every clue in a case is vital when building a criminal profile because it reveals important characteristics of the killer. In a criminal case that lacks evidence and involves a random selection of victims, like that of the Tylenol murders, the chances of constructing an accurate profile is significantly diminished.

Nevertheless, it is often times an essential tool that can assist investigators, to a degree, in their search for a perpetrator. However, it has been argued that a criminal profile also has the ability to mislead an investigation. The accuracy of a profile is only confirmed when the perpetrator has been caught and their characteristics can be measured against the biographical sketch drawn from evidence.

Journey into Darkness

John Douglas and Mark Olshaker's book Journey into Darkness provides further insight into the Tylenol terrorist. The authors write that the killer was likely a loner who was motivated by anger directed at society in general. It is possible that the killer may have had some kind of psychiatric treatment in the past to help deal with extreme feelings, such as depression, anger, anxiety and control issues.

It was also suggested that the Tylenol terrorist could have openly complained at some point about society's wrongdoings against him or her. If correct, the terrorist could have attempted to contact a person of power, either by letter or telephone to resolve matters. There is a chance that the killer may have perceived that those he contacted refused to take him seriously, further fueling his anger and resulting in the random deaths.

The likelihood of the killer living in the Chicago area is high because he seemed to have had knowledge of the surrounding area and local stores. The killer is believed to own a car or truck, which would enable him to drive the distances between the store locations where the tainted bottles were planted. According to Kowalski, who also constructed a profile of the killer, it is likely that the killer may have worked in a profession where cyanide was easily obtainable, such as the gold and silver mining industry, film processing or chemical manufacturing. He further stated that the killer probably held a menial job with low wages.

The profiles that were constructed of the Tylenol terrorist have been criticized as being too general to be of any assistance in an investigation. They have provided some insight no matter how limited, into the personality, behavior and lifestyle of the killer.