Can the Police legally tow my car away without telling me or giving me a citation?

I purchased a police car 1 month ago from San Diego, they didn't have the pink slip.The letter of sale says as soon as a replacement title is obtained from the DMV it will be certified mailed to me. When I saw the tow truck I ran outside & told them that it was my car & showed them the paper work & insurance. They said it didn't have my name on it (it does) & was not registered. When I asked them if I could park it in my drive way, they said NO the tow truck is already here. I did not rec. a citation. The San Diego PD picked it up & delivered it to me.Now there's s a terrible consistent ca-bang sound, the tow co said to have a mechanic show them that the tow truck caused it. Do I have a civil case against the officer's for towing it?

You have one against the City as well as the officer who towed the vehicle and the tow company. If you purchased it from the agency that towed it you have a case.

If you provided proof of ownership and the reasons for not having it properly tagged as the fault of the San Diego PD - the officer had a duty to inquire further with his agency in regards to the vehicle. His failure to properly perform that duty showed and demonstrated his incompetence. The officer and or his supervisor could have stopped the vehicle from being towed regardless of whether or not the wrecker arrived to take your vehicle

You should have the vehicle inspected. The exact reason or cause of the damage should be recorded on the inspection. If the inspection expert sites damage caused by the wrecker the case is stronger.