
Ted Kaczynski's brother turning in the infamous Unabomber is a well-known part of the case, one covered in Netflix’s new film Unabomber where the luddite terrorist is played by Jacob Tremblay.
What is less known however is the frayed relationship the two shared, along with David’s attempts to reconnect with his brother before he died by suicide in prison in 2023.
Netflix's film shows how David Kaczynski turned in his brother to the FBI in 1996, 17 years after he began his lone wolf terrorism campaign of bombing that led to three deaths and injured 23 others.
David had spotted his brother’s idiosyncrasies in the Unabomber’s manifesto after his wife encouraged him to read it and decide if it sounded like his brother.
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Ultimately, he called the authorities, helping them confirm that Ted Kaczynski was indeed the Unabomber.
David caught his brother by spotting an odd phrase in his manifesto, but he had been estranged from Ted for seven years

David and Ted were close friends throughout their entire life, with David speaking about how he felt he was responsible for teaching Ted how to navigate the social world.
Ultimately however David’s marriage to his wife Linda Patrik caused the split between the brothers, with Ted cutting off communication with his brother over his wedding plans.
As shown in Netflix’s true crime film Unabomber however Linda encouraged David to contact the FBI when the Unabomber’s manifesto was released, stating that it sounds like him and could fit with the former maths genius due to his isolationist lifestyle. One of the particular phrases involved him saying that ‘you can't eat your cake and have it too’, an odd change to a popular phrase which stood out.
The brother contacted the FBI, in part hoping it would disprove his wife, and provided letters and documents written by his brother.
The FBI, discussing how Kaczysnski was caught, said: “David provided letters and documents written by his brother. Our linguistic analysis determined that the author of those papers and the manifesto were almost certainly the same.
“When combined with facts gleaned from the bombings and Kaczynski’s life, that analysis provided the basis for a search warrant.”
David attempted to speak to his brother for years whilst he was in prison, but he never replied to his letters and spoke about whether he regretted it in his book
Ted’s brother has spoken on multiple occasions about his repeated attempts to contact his brother in prison. None of his letters or correspondence received a reply.
He sent a ‘vicious’ letter to David after he was captured, and later wrote in 1999 that he would only renew contact with him if he split from his wife and changes his ways to work against modern society, saying: “In this way, he would not only earn my personal forgiveness; what is more important, he would be cleansed and redeemed of his treason against the values that he once held in common with me and many other people.”

Speaking in his book Every Last Tie, David revealed that whilst he regrets that he had to make the decision he did, he does not regret turning in his brother. He explained: “I still look back on the decision and know it had to be done.
“He could have and probably would have killed other people. … If there was any way out of having to do what I did and still be a responsible human being, I would have. But I had a responsibility. As painful as it was. As it still is.”
David and Linda retired from their jobs at a Buddhist monastery in 2015 and moved to Texas, a year before he published his book. He later connected with the families of Ted's victims, becoming friends with some of the family members and giving lectures on mental illness.
Unabomber is available to stream on Netflix now.
Topics: True Crime, Netflix, TV and Film, Film, Crime