at the end and it be clear that the murderer plant the murder weapon in mrs. columbo car and it be at the police ballistics lab . but where do the gun under the hood and use in the demonstration and come from . wouldn not the murderer have clear out the stuff under the hood . they have a whole week . or do columbo cop replicate the camera or gun under the hood use in the demonstration . how do they do that without break and enter the car . perhaps this be why the murder seem surprised at the end . but how could columbo have replicate their camera or gun device and get it calibrate to their key fob . columbo must have get the gun back from ballistics and have it re plant under the hood of the car and and be very lucky that the rest of the device with camera be still there and transmit . this be a positive show until this glaring plot error at the end .