[woodbutcher1963]

I believe it was Kaczynski’s brother that recognized his hand writing or writing style and called the feds.

[oldvirginian]

“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.

[Repeat Offender]

Not to split hairs - The documentary I saw, with interviews of the family, the sister in law read the manifesto in the paper (WaPo?) and told her husband, (Kaczynski's brother) that, 'this sounds like Teddy.' Her husband agreed and notified the authorities. The brother (and his wife) then provided information on Kaczynki's last known location(s). A quick search corroborates this: It was the sister in law who first suspected Kaczynski and convinced her husband to look further

My point is - the article reads as if some super sleuthing was conducted to ID and locate Kaczynki and to arrest Rudolph and therefore the "G-man's" bona fides are established and his opinion is trustworthy.

In reality - he got lucky because Kaczynki's family turned him in when the FBI et al had hit a wall.

Also, while Rudolph may have eventually been caught.....this was not until after they tried to frame Richard Jewell for the Olympic Park bombing by asking him (Jewell) to help with a 'training scenario' and write down (confess) how the bombing was done from his point of view.

Luckily, Jewell felt something wasn't right and had the presence of mind to contact his attorney. Congressional hearings on FBI's handling of Olympic Park Bombing

The "G-man" is entitled to his opinion....I don't know how much I would trust it. Your mileage may vary.

[Mr Ramsbotham]

I believe it was Kaczynski’s brother that recognized his hand writing or writing style and called the feds.

Actually, it was his brother's wife, who convinced the brother to go to the authorities.