As I understand this (having talked to locals) Ted was in trouble and suspected of committing crimes, almost from the minute Ted's brother David moved Ted into the cabin. David was aware that Ted was 'a problem' and that had been going on for years with his brother - but what to do? The reason David bought the cabin and moved Ted into it was not just to give Ted a life, but to keep him isolated from the world and trouble. David was struggling just to keep his own life and family going.
Ted was brought up on local/area charges several times where he lived, prior to him being identified as the Unabomber. Charges against him always failed due to 'lack of proof'. (poisoning people's dogs, dropping boulders on railroad tracks, destruction of railroad property, various thefts in the area ...etc...) ... in spite of all of that Ted continued to circulate in the local community and as far away as Helena where he went out of his way to meet a reporter at a Helena newspaper (a former classmate of mine at SUI !). Ted was out there in the public domain, well known ... several people had speculated that he might be ;'DB Cooper' but that was dismissed easily because of Ted's age and his appearance - he did not fit the Cooper profile even remotely. When the FBI finally identified Ted they had to move very quickly and quietly so as not to tip off anyone, including Ted. Their plan for taking Ted down worked or Ted would have fled into the mountains. Ted had fled law enforcement before and had vanished for days ... he always had a survival kit and a gun ready just in case.. on this occasion with the cabin encircled, an Agent just walked up and knocked on the door and Ted answered the door and it was over.