There is a growing interest in law formalisation, however some legal domains are traditionally considered to be more “computational” and therefore more amenable to formalisation than others. For example, tax law has several available implementations. One example is formalisation of the French tax law in Catala – a domain-specific language that takes a semantically principled (and functional) approach to law formalisation. Among the legal domains that are traditionally seen as less “computational” and requiring human interpretation, stands criminal law. We will discuss work in progress in formalising computational fragments of criminal law in Catala, and outline the challenges of extending the frontiers of law formalisations to this domain.