Here's what Gutting, commenters above, and many others are missing:

Even if we assume (for the sake of argument or by actually accepting the premise) that 100% predictability is NOT inconsistent with free will, the key fact is that at no point in time is the individual able to alter the course leading to the pre-conditions that determine the decision or action in question.

Let's say anyone who knows me well (and I myself) could predict with virtual certainty that, if I were handed a gun right now and given the option to shoot someone on the street, I would choose NOT to do so. That's because of "the kind of person I am" (and the fact that I'm not in any altered/abnormal mental state), which some would argue means it's still part of free will.

But "the kind of person I am" is not something over which I've ever had any control, and neither are any of the physical conditions (inside and outside my brain) immediately preceding and causing (determining) my decision. If you disagree, tell me at what point in time I could have asserted any control. We have the physical conditions existing immediately prior to (and causing) the decision, and those conditions were caused by the conditions immediately preceding that state, and so on all the way back to the twinkle in my father's eye.

This commenter has it right, in my opinion. See my Two-lever argument.