The Unabomber — Ted Kaczynski's 17-Year Mail Bomb Campaign

The Case

The Unabomber case is one of the longest and most expensive domestic-terrorism investigations in U.S. history. Between 1978 and 1995, a single offender — later identified as Harvard-educated mathematician Theodore John Kaczynski — sent or planted at least 16 increasingly sophisticated bombs that killed three people and injured 23 more. The FBI codenamed the investigation 'UNABOM' because early targets were linked to universities and airlines. The case ended only when Kaczynski's own brother recognised his distinctive prose in a published manifesto and contacted the authorities.

The Crime

Kaczynski's first device was discovered in May 1978 at the University of Illinois at Chicago. Over the following 17 years he mailed or planted bombs aimed at academics, airline executives, computer-store owners, geneticists, and advertising and timber-industry figures. According to the Smithsonian National Postal Museum, nine of his 16 known devices were delivered through the U.S. mail, which placed the case squarely under federal jurisdiction and brought postal inspectors into the task force.

The bombs grew more lethal over time. Early devices caused burns and shrapnel injuries; later devices, built with carefully machined wooden boxes and homemade explosives, were capable of killing instantly. Kaczynski deliberately filed off serial numbers and used untraceable components, frustrating forensic examiners for years.

In September 1995, after threatening further attacks, Kaczynski persuaded The New York Times and The Washington Post to publish his 35,000-word essay, Industrial Society and Its Future — better known as the Unabomber Manifesto — which argued that modern technology was destroying human freedom.

The Victims

Three people were killed during the campaign, according to the Cornell Law School UNABOM chronology:

- Hugh Scrutton, 38, owner of a computer rental store in Sacramento, California, was killed on 11 December 1985 when he picked up a package bomb left in the store's parking lot. He was the first fatality of the campaign.

- Thomas Mosser, 50, a New York advertising executive, was killed at his home in North Caldwell, New Jersey on 10 December 1994 when a mailed parcel exploded as he opened it.

- Gilbert Murray, 47, president of the California Forestry Association, was killed on 24 April 1995 by a package bomb sent to the association's office in Sacramento.

Another 23 people were injured, several of them maimed for life, including academics at Yale, Berkeley, Vanderbilt and the University of Michigan.

Investigation

The UNABOM Task Force, led by the FBI with the ATF and U.S. Postal Inspection Service, became one of the largest manhunts in U.S. history. Investigators built detailed profiles of the offender from bomb residue, recovered components and the language used in his letters, but had no suspect for nearly two decades.

The decisive break came after the manifesto was published. David Kaczynski read the text at his wife's urging and noticed phrases and ideas that matched letters his brother Ted had written years earlier. He contacted a lawyer, who passed the information to the FBI. As detailed in files from the case's lead prosecutor held by the National Archives, the tip transformed a stalled investigation into a focused operation.

On 3 April 1996, federal agents arrested Kaczynski at his 10-by-12-foot cabin near Lincoln, Montana. Inside they found bomb components, 40,000 pages of handwritten journals, draft versions of the manifesto, an original typewriter matching the manifesto's typeface and — crucially — a live, fully assembled bomb ready to be mailed.

Trial and Verdict

Kaczynski was indicted in federal court in Sacramento. He initially sought to represent himself and clashed with his court-appointed lawyers, who wanted to mount a mental-illness defense he rejected. Facing the possibility of the death penalty, he pleaded guilty on 22 January 1998 in the U.S. District Court for the Eastern District of California. On 4 May 1998, he was sentenced to four consecutive life sentences plus 30 years, with no possibility of parole.

Today

Kaczynski was held at the federal supermax prison ADX Florence in Colorado for most of his sentence before being transferred on medical grounds. He died in federal custody in June 2023. The case continues to generate documentaries, books, podcasts and academic debate — both about the FBI's forensic and behavioural work and about the disturbing afterlife of the Unabomber Manifesto, which has been cited by later extremists. The Unabomber case remains a touchstone for discussions of lone-actor terrorism, mail-bomb security and the limits of profiling.