Though Mark Hofmann was considered a potential perpetrator by the local authorities before the final bombing was in the books, he wasn't exactly the strongest of suspects. From what authorities knew after the first two bombings, Hofmann had a meaningful connection to Christensen because of the depth of their work on the McLellin collection, but his connection to Sheets was rather weak. Of course, that was the reason Hofmann planned the Sheets attack from the beginning.
With the only ties between Hofmann and the others being the McLellin collection and the Salamander Letter, authorities believed, according to The Washington Post, that they were looking an assassin hired for one of two motives. The first, and the one they considered to be the most likely, had to do with Sheets' company, CFS. As the LA Times pointed out at the time, the company had been on a downturn, sustaining heavy losses and probably angering a few clients along the way, and since Christensen had only recently resigned from CFS, both of the victims had stronger ties to the company than they did to Hofmann.
The other possible motive questioned by investigators had to do with the controversy surrounding the Salamander Letter, but it wasn't Hofmann they were worried about right off the bat. Instead, they believed the attacks could've been committed by a member of the Mormon church or at least ordered by someone for similar religious reasons, a line of thinking that would make Hofmann a target.
