Ohio judges are opposing a bill that requires first-time drunken driving offenders to have devices installed on their vehicles to test their sobriety. The Ohio Judicial Conference says the mandatory requirement removes discretion that judges need to determine the best penalties for first-time offenders. The proposal by state Reps. Terry Johnson and Gary Scherer would require the devices for convicted first-time offenders who regain limited driving privileges during the usual six-month license suspension. It beefs up current law, which makes the interlock devices mandatory only after a second conviction. The devices, which require drivers to blow into a sensor, prevent vehicles from starting if a certain amount of alcohol is detected. The systems cost about $75 a month, usually paid by the offender.