It didn't happen last year when Neenah police investigated a similar case.
Green Bay Police said they don't expect an arrest. They said it's hard to backtrack to a source unless a person comes forward.
"It's real hard to isolate the area, specific homes and anything like tha," Kaufert said.
Mayor Kaufert says he'll see if the city can do anything different on future Halloween, but that doesn't mean clearing the streets.
"I'm not going to be the mayor that bans trick-or-treating in Neenah, so parents just have to be careful," Kaufert said.
City leaders said that ultimately, it's up to parent's to keep kids safe this and future Halloweens.
The following Wisconsin police departments have reported tainted candy given out in their communities in 2017: