"A man came to the front lobby and dropped it off," Neenah Police Chief Kevin Wilkinson told ABC News. "He found it in a collection of money for Girl Scout Cookies."
Neenah Police Investigator Adam Streubel told The Arizona Republic he was doubtful much could be done with the message to solve the Arizona case.
“There’s no way to trace (the bill),” said Streubel, who suspects the message could be a joke.
“There was a little spring of hope for a second, and then reality set in,” Streubel said. “There is nothing you can do with it, which is rather frustrating.”
One of Mikelle’s younger sisters, Kimber Biggs, is also doubtful.
"The fact that her name was spelled wrong was, you know, is kind of discredited," Biggs told The Arizona Republic Tuesday. I don't think that would be something she'd do."
Biggs said she found out about the bill when a photo of it surfaced on a Facebook page she runs called Justice for Mikelle Biggs.
“I was looking at the bill, trying to look at the handwriting and see if it could mean something and I got sick about it," Biggs said. “‘Is this a hoax?’ ‘Did someone play a cruel joke?’ and that made me upset or 'Is it real?' and even the thought of that upsets me if it’s real."
Mesa, Arizona, police Detective Steve Berry told KPHO that his department plans to look into the note, even though changes of finding DNA or fingerprints are low.
“Anytime we get new information that may resolve this case and give closure to the family and community we make every effort to validate or invalidate the lead,” Berry said. “If there’s any information that can be garnered from that, we would certainly find that.”