The concept of free will is a problematic basis for assessing legal accountability.
First of all, free will could never have evolved in a world of ordinary biological pressures. There is, moreover, substantial experimental evidence against it. This evidentiary situation is a serious moral concern because free will ideology plays a key role in justifying punishment in criminal law. People draw a sharp distinction between the suffering of innocents and suffering that is deserved. As a basis for criminal punishment, the very concept of just deserts usually presupposes that wrongdoers have a choice in what they do.
The essay proceeds from the assumption that hurting people is presumptively wrong and therefore requires justification. If this assumption is true, then the factual dubiousness of free will presents a serious problem for current penal practices. Because the evidence makes free will unlikely and the logic of evolution makes it impossible, an important underpinning of the criminal law appears to fail.
A variant of free will, so-called compatibilism, does not solve or avoid the problem of justification. To the contrary, it seems on closer analysis to be merely a repackaging of an ancient form of virtue-ethics under which people are deemed to deserve to suffer because they are what they are.
Humbach, John A., "Free Will Ideology: Experiments, Evolution and Virtue Ethics" (2010). Pace Law Faculty Publications. 636.