I'm looking for information re: gacy videotape

I recently aquired from a street vendor in New York a videotape which is essentially a two hour clip show of news and television coverage relating to the impending execution of John Wayne Gacy. It starts with the famous interview he did with channel two news in Chicago and proceeds to show all sorts of different clips, including a giraldo-esque talk show where some of the victim's families were there along with GG allin's brother and a young girl who was Gacy's pen pal. There is a live scene from one particular mother of a victim's living room in the minutes leading up to the execution. There is all sorts of great stuff, and the whole thing is, though amateur, very well put together. It has a printed cover and the labels on the tape are written in somebody's hand. I was wondering if anyone could give me some info as to this tapes origin, as I find it rather fascinating and am intrigued by it. Thanks.