All four of the packages were sent without a return address, and bomb sniffing dogs reacted positively to the boxes when they were discovered. According to investigators, that's probably due to the fact that film uses some of the same chemicals as common explosives. From what everyone can tell, the sender was simply trying to get his ideas for a new turn signal to Toyota R&D. He certainly got their attention.
According to the Charleston Gazette, the FBI has no intention of tracking the engineer down or charging him with anything. The agency said that the whole thing was a simple misunderstanding.
[Source: The Charleston Gazette | Image: Rusty Jarrett/Getty for NASCAR]