Was it Real??? Texas Chainsaw Massacre?

There is a new remake of (Tobe Hooper's) Texas Chainsaw Massacre coming out soon, my question is it a true story or based upon a true story? This is a quote from the new movie:

On August 20th 1973, police were dispatched to the remote farmhouse of Thomas Hewitt, a former head-skinner at a local slaughterhouse in Travis County, Texas. What they found within the confines of his cryptic residence was the butchered remains of 33 victims, a chilling discovery that shocked and horrified a nation in what many still call the most gruesome mass murder case of all time.

I did some searches and only come up with movie info I would like to read about the real story if there is one. Can anybody help? Seems to be based on a real guy here is another quote I found:

Tobe Hooper's horror masterpiece is based on the same criminal Alfred Hitchcock based "Psycho" on.

Thor,
The movie is based on a true story,but rather exagerated quite abit. I do not have full details,but there were some murders committed just how many I am not sure.It went on for quite awhile till the guy was caught.

a footnote: The house used in the original movie was located about 5 to 6 miles just up the highway from my home.I worked with a fellow technician some years ago who actually lived and grew up in that house before the movie was ever filmed there.
For awhile before it was torn down there was a faint remains of a driveway going up to the home with grass starting to cover it up you could see from the highway blocked off by a barbed wire fence.The highway that the girl runs out onto at the end is still there just widened.
I was told many movie props could still be had if you snuck up there at night without the cops catching you.
The most bizzare thing I ever saw was the freaky bone constructed chair Grandpa sat in for sale in a local pawn shop.
Cannot remember if Grandpa's chair was in the first movie or the sequeal? Been a long time since I viewed either one.

Sorry I did not have any actual facts. I have always wanted to know the real truth behind it all not the Hollywood version.

It happened in Childress,Tx. I was told the sawing was done in a old meat packing house of which there were, back then, at least one in every county. Lots of cattle and swine around there.