HELP!, my car was hit by a police cruiser Options

[nics]

while i was on my way home last night with my brother and my cousin, cruising to a stop then suddenly a car hit me on the driver side and then i realized that it was a police cruiser. he beat the red light continued driving 3 more blocks. called 911 and cops came in. thank God no one was hurt.

they told me that the cruiser was malfuntioning because of the gadgets hooked up in the car. the cruiser came from an alley, my cousin noticed it but i didnt because i didnt see any lights on including the siren. this happened around 9pm. the one driving the cruiser told the investigating officer that he was parked at the corner of the alley, he was applying his brakes then suddenly his car revved just like that and when the time that he hit my car, he said he put it in parking gear. I DONT KNOW IF ALL HE SAID WAS POSSIBLE!

i called my insurance and let them know what happened. the investigating officer told me that it was definitely not my fault and the insurance would take care of it.

i dont know what to do now...
im really pissed off!
seems like i would sue them!

any advice or help from you guys? thanks