Truth behind the Texas Chainsaw Massacre?

Hi. Can anyone tell me what the REAL story behind the Texas Chainsaw Massacre is? I have read in the past that the story was actually inspired by the crimes of Ed Gein. Lately though I seem to be coming across refrences that the attribute the inspiration for the movie to someone named Thomas Hewitt. The supposed Hewitt murders are said to have occured in 1973 in Travis County, Texas and are described in such a way as to be closer to the events of the movie(s). Unfortunately, all the Thomas Hewitt refrences seem to occur in relation to web-pages concerning the new Texas Chainsaw movie, wich makes me think that the name and events are just created elements to form a backdrop to the new movie. Does anyone among the teeming masses know the real true story here?

I found this here

I also read this in the NY Daily News yesterday or the day before so I figure it’s true.

Barnes and Noble says it’s based on Gein too.

Cecil’s column on the subject:

And finally, so does the IMDB in it’s bio of the writer.

Oh, and welcome to the SDMB.

Snopes just covered this too.

Outstanding job to one and all! Thanks so much for helping me with this!

[slight hijack]
Gein also inspired Psycho and (certain aspects of) the Silence of the Lambs