A political “whodunit” is brewing in Davenport. The riddle to be solved here is just who used the FAX machine in the Davenport police department to send a memo to the media. The memo accused Lieutenant Phil Yerington of treating some cops unfairly and it accused him of being involved in a cover-up of sick leave abuse. The memo is apparently a fake. Yerington, who was once Davenport’s mayor, is now running to become the Scott County Sheriff. The former police chief of an Illinois town has been hired to solve this whodunit. The state Department of Criminal Investigation refused to investigate because it’s not a felony to FAX the media a memo. The police chief turned private eye is being paid 60 bucks an hour, plus expenses, to investigate.