I was sitting with my two brothers in their backyard around 8:15 in the evening when one of my brothers noticed this thing flying around in the sky. At first we all believed it to be a radio controlled flying toy of some sort. I then decided to video tape it and wished now that I taped the entire duration of this flying object. This thing would abruptly change directions and would also continuously flash green and red lights. It was also very fast. At that time I honestly did not and never have believed in UFO's. Since I was not a believer, I stopped taping, but kept watching. The entire ordeal lasted approximately 15 minutes then was gone as fast as it appeared. I decided to send my video only when I read a local article about a UFO sighting in the area and thought possibly what we saw was also a UFO.