Kevin, have you been able to get a look at the bucktags?
Also, if it's an ex-CHP unit, you may be able to still see a four-digit number applied to the driver's door above the cert label as shown below:
Number should show up even if it's painted over as it is applied with a paint pen and will be viewable in relief (unless it's been sanded off). You should also find red reflective tape, or evidence of some, on both doors.