Free will pretty much implies a soul of some sort, so a true materialist does not believe in free will. I consider myself to be a true materialist.
That is in fact not true at all. There is a very tiny, outside possibility of free will being recovered from quantum mechanics if and only if it turns out that quantum "random" processes are actually admissive of conscious control. (The more commonly cited "quantum randomness means no determinism, therefore free will!" case, though, doesn't hold up because randomness is
also not free will; if your decisions are purely random, you have no more freedom to choose than you do if your decisions are predetermined.) This would basically fall under the umbrella of discovering new laws of physics compatible with free will, which (as a physicist) I must remind you is always possible.
Personally, I'd be in the "there is no free will" camp too if it didn't pose serious threat to meaningful jurisprudence. How can we meaningfully deter criminals if free will didn't exist?
Not to mention, the assumption that free will doesn't exist also enable oppression and restriction of freedom.
Can I file this statement under "things that made me absolutely terrified today"? I can't comprehend the idea that a factual statement about the world should be determined true or false by its
moral consequences. Gravity also enables oppression and restriction of freedom...