TexasCHLforum.com

Perhaps you can get a video camera with DVR recording and point it at your parking place.
If you think you see weapons tell the 911 operator that.
When (If?) the police arrive file a trespassing complaint.
Or you could wait for them to leave, go to their houe and kick their car. Not very advisable.

I reported some people who were stealing a car in front of my shop in mid-afternoon. The cops arrived an hour later and I showed them the video including the faces of the thieves, the act of breaking into the car, the car leaving and the plate of the car the thieves arrived in. Nothing done.
I had a thief brek in to my shop at night. Called the cops when the alarm went off. Saw the thief on computer from home and have a great shot of his face. Cops arrived, I tracked the thief on video and was on the phone with the cops at the scene telling them where he was. No puirsuit. No followup other than a report the next day. The cops were gone by the time I got there and the thief was one block over waiting for us all to leave so he could go back in. Called cops again. No response since "he wasn'tdoing anything". Well, he WAS going over the things he stole from me on the hood of "his" car to see how much he got. I tried to ride over and he took off. I stayed till next day.
What do they need, us to chase the bad guys down ourselves? Very frustrating.