4.9 Activity level propositions

Activity level propositions relate to activities and do not assert criminal liability. This makes them one step below the offence-level propositions in the hierarchy; the activity may have been criminal but it also may not have been. In Table 4.1 we have:

• \(H_p^4\): The defendant kicked the claimant,
• \(H_d^4\): The defendant was not present when the claimant was kicked.

If \(H_p^4\) is true, then this may have been done lawfully depending on the context. However, if \(H_p^4\) is proven true to the fact finder, then it could provide a large step closer to answering the ultimate issue – all that remains is to show that the activity amounted to assault, which addresses the offence level proposition \(H_p^2\).

Forensic scientists do consider activity level propositions where scientific findings can assist the court on them. In fact, this is the advised level of proposition for the scientist to address due to its importance in the hierarchy. In order to consider activity level propositions, it is often necessary for the expert to take in to account contextual information from case circumstances as well as the available scientific findings. If the necessary contextual information is unavailable, then the scientist may find themselves unable to assist the court regarding alleged activities. The same might also be true if there is a lack of scientific understanding relating to a piece of scientific evidence being interpreted in light of asserted activities. To make sense of this, consider the propositions:

• \(H_p^3\): The defendant fired the gun,
• \(H_d^3\): The defendant did not fire the gun.

Finding gunshot residue particles on the defendant’s clothing might not be enough information for the scientist to assist the court on these propositions. They might require further information about relevant case circumstances in addition to results from the scientific literature about the background abundance and transfer and persistence of gunshot residue particles.