“I believe it was Kaczynski’s brother that recognized his hand writing or writing style and called the feds.”
YES!
I saw an interview with Kaczynski’s brother. He said that after the FIBbies released some letters and stuff to the press the wording and style of writing kept knocking on his brain. He had some of Ted’s old college papers in his attic. He compared the old to new. A few days of soul searching later he call the FIB.
He said he hated to turn his brother in, but what Ted was doing...
He has no regrets other than not being able to save his brother from doing evil.
Not far from my present home, just a bone's throw to where the griz killed the Cali dame.