A Warren police officer has resigned from the force and will be on probation for one year for collecting at least $20,000 for overtime he never worked.Ryan Pylak, 41, pleaded no contest Wednesday in 37th District Court to one count of false pretenses between $200 and $1,000.The no contest plea - which is not an admission of guilt but treated as such for sentencing purposes - was part of a plea agreement with prosecutors that called for him to resign from the Warren Police Department and immediately pay restitution to the city.