We consider the case where a scientist is required to assist a court
of law by providing an evaluative opinion with regard to the assistance
that a set of scientific observations might provide in addressing
matters that the court is deliberating. We confine our selves to criminal
law but believe that the principles extend analogously to the civil law.
For the purpose of simplification we consider the situation where a
single defendant is on trial for a stated offence. Then the scientist's
evaluation should be governed by the following principles: