Partly. The movie takes some elements from real events but also adds fictional elements for dramatic effect. The character and storyline are not a direct account of a specific true story but draw inspiration from similar real-life horror.
The Texas Chainsaw Massacre has some roots in real-life horror, but it's not a straightforward retelling. It takes cues from real serial killer cases and weaves them into a fictional narrative that's designed to shock and scare.
Yes, it was loosely inspired by the crimes of real-life serial killer Ed Gein.