TL;DR Garrett has a Fredbear plush, and there are no plushies of Fredbear in Freddy’s Fazbear Pizza. Meaning that Garrett was killed in Fredbear’s, meaning Fredbear’s is in Nebraska.

This theory does use deleted scenes and cut content to support it, so do keep it in mind.

I have my doubts with Henry existing in the FNaF Movie, as it is mentioned that there was only one person who started up Fazbear Entertainment in the movie lore. This would mean that if Henry does exist, he would not be the same Henry from the games or books.

I think the reason for why William Afton was in Nebraska during Garrett kidnapping is because of a business he ran. This business being, Fredbear’s Family Diner.

The actor of Garrett confirmed he had some scenes in Freddy’s Fazbear Pizza, but they were removed. These scenes featured Garrett holding a Fredbear plush.

It appears custom made, but I can’t tell. Either way it shows us that Garrett’s death has some connection to Mike’s brother from the games, aka the Crying Child. We already knew this connection, but it considering that Garrett wasn’t shown to have this Fredbear plush anywhere else in movie means something very sinister. Garrett having a Fredbear plush means that William Afton had to give it to him, so that means Afton probably used this plush to lure Garrett away.

We also know that there are no visible Fredbear plushies in Freddy’s Pizza Place, meaning he had to be killed in Fredbear’s. If Garrett was killed at Fredbear’s, it would explain why William Afton was in Nebraska. Nebraska is where Fredbear’s Family Diner was located, and Fredbear’s Family Diner is Afton’s business.

He probably moved to Minnesota just to get away with the crime he committed in Nebraska.