Federal investigators return to unsolved crime.

In the autumn of 1982, 7 people were killed after consuming Tylenol (JNJ) capsules that had been laced with potassium cyanide by an unknown assailant.

Nearly 27 years later, the still-unsolved Tylenol murder case is being reopened.

Working off advances in forensic technology and a new influx of tips after the incident's twenty-fifth anniversary, federal investigators decided to review all the evidence again. Chicago's division of the FBI will be working in conjunction with the Illinois State Police and local departments on the cold-case investigation.

Continuing with their best lead from 1982, agents searched the home of James W. Lewis, who was arrested on an extortion charge related to the case. Lewis had sent Johnson & Johnson a letter demanding $1 million if the company wished to "stop the killing." Though he denied having anything to do with the murders, he was sentenced to 12 years in prison, and remains a prime suspect.

Tylenol manufacturer Johnson & Johnson was praised for its swift response to the crisis: All Tylenol products were removed from the shelves nationwide - even though the only reported cases occurred in the Chicago area. The company released extensive consumer warnings, and offered exchanges to anyone who had already made a purchase.

As a result, the company posted heavy losses. It rebounded in less than a year, however, following the introduction of tamper-proof packaging, which led to widespread adoption of hermetically sealed bottles.

Due to the company's swift action, Tylenol remains one of the most popular over-the-counter painkillers on the market.

Check out Minyanville's look at some of the most infamous product recalls in history.