Here's where natural law can be recognized--and help--100% of all justice and jurisprudence is predicated upon free will exercise. In other words, we exonerate someone who kills another if, for example, they were so badly abused by the person they struck down, they are considered to have had no free will choice in the matter... "she abused and abused and abused me, and one day, I snapped, and snapped back". In contrast, we incarcerate murderers who use their free will.
Put into other words, it is commonly accepted/natural law that all whole, well persons exercise free will and free will is only lost when one is mentally infirm/abused/a child not yet fully formed.
Here's a summary from a paper I wrote on the subject in 2017:
Summary
Arguably, all of jurisprudence holds individuals and groups responsible for a myriad of free will choices. Persons and juridical persons with legal capacity are held responsible for choosing to enter into contracts and agreements,
[1] criminals and tortfeasors are held responsible for choosing unethical and/or unlawful behaviors. Yet in some cases, a soft determinism aka the theory of compatibilism (free will and determinism are compatible ideas), has been invoked by the courts. Actions caused by an addiction or compulsion have been construed as exonerating the accused and even to shift the responsibility for lawless acts to another party, one who manipulated the accused as their puppet agent.
In justice systems modern and ancient, the single-most important justification for correction or punishment is that degree of guilt hinges upon free will choices to act unlawfully or as a tortfeasor. Millennia of philosophical debates add to recent discoveries in the fields of genetics and human behavior, however, questioning man’s assumptions regarding the power (and even the existence) of human free will.
[2]
[1] Emerson, Robert.
Business Law. Barron’s, 2015, page 129.
[2] Jones, Matthew.
Overcoming the Myth of Free Will in Criminal Law: The True Impact of the Genetic Revolution. Duke Law Journal, Vol. 52:1031, 2003,
"Overcoming the Myth of Free Will in Criminal Law: The True Impact of t" by Matthew Jones. Accessed 29 March 2017.
http://scholarship.law.duke.edu/cgi/viewcontent.cgi?article=1187&context=dlj. Accessed 30 March 2017.