Investigators soon determined that the tainted Tylenol capsules hadn’t been tampered with at the factories where they were produced. This meant that someone had taken the bottles from store shelves, laced them with poison and then returned them to grocery stores and pharmacies, where the victims later purchased the tampered bottles.
The Tylenol murders, which inspired copycat crimes involving other products, were never solved, although various individuals were investigated. However, a positive outcome of the crisis was that it led drug makers to develop tamper-proof packaging, which had been largely nonexistent before the Tylenol Terrorist struck.
