Starting Sept. 25, the Police Department will host a Citizen’s Police Academy aimed at informing participants about topics running the gamut from crime prevention to the workings of the state’s court system. These 6 to 9 p.m. sessions on Wednesdays through Dec. 11 at police headquarters, 54 Park St., are free to residents 17 years of age and older who do not have criminal records. For more information or to register, contact Sergeant John MacDonald at 978-772-8200, ext. 570, or visit www.ayer.ma.us. Full story for BostonGlobe.com subscribers.