Triangular-shaped UFO spotted over Elk Grove during night

On December 18, 2016, a dweller of Elk Grove (California) was working in his garage. By looking up in the night sky, he noticed a black triangular-shaped UFO with lights on the corners. Object had an impressive rate of speed.

Witness report:

I was working in my garage cutting some foam to cover some accent windows in my house for privacy, I had just installed some of the foam into a window so I went outside to see how it looked then I went to the bank yard, there's a lake in my back yard, I took a picture of the reflection on the lake and started walking back to my house. For reason I looked up and saw a triangular shape moving at a high rate of speed, it was highlighted by thin dim lines of the triangle with lights on the corners of the triangle with halos around them. The triangle went in a straight line and I lost sight of it behind my plum tree, I tried to follow it but it disappeared. I wasn't scared, I stayed out there for another ten minutes or so so I could see if I could see anything else. I didn't see anything else. When I went back inside I started freaking out, because of what I saw and how close it was to my house and family.