UFO seen Christmas Eve 1987. Made sudden "L" shape turn unlike any known aircraft.

The following incident occured in Exeter, Rhode Island on Route 102.  It was Christmas Eve 1987. I was 9 years old.  I was carrying presents out to the car at about 8 PM.  I looked up into the dark sky and saw a rectangular shaped UFO.  It had lights that were white, red and green. It appeared that in the white lit "windows" there were shadowy heads.
Things became more unusual when the object stopped while moving in a straight line and suddenly turned on a dime in an "L" shaped line.  
Too frozen in awe to move until that point (seemed like I watched for up to 1 minute), I ran into the house to get my mother.  By the time she came out with me (a few seconds later) she and I caught the tail end of a flash as the object had quickly taken off.
Even though we both clearly recall the incident 26 years later, she was only able to see the tail end of the object and the flash.  This confirmed to her that I had infact seen something unusual.
The witness will have his mother submit a report, as well.  PD