The headlight control switch is bad. If you go to your fuse panel you will find a 15 amp fuse for the lights. Disconnecting the battery will shut off lights. You need a new headlight switch with auto control.
In a 2000 Dodge Intrepid there is no way to turn them off. They are called daytime running lights, you may notice them on after the car has been shut off as well. But they will shut off momentarily.