Can a government entity be deemed to have engaged in a constitutional violation by virtue of policy, policy or custom or failure to train?

`absent the conscious decision or deliberate indifference of some natural person, a [governmental entity], as an abstract entity, cannot be deemed to have engaged in a constitutional violation by virtue of a policy, a custom or failure to train.' [Citation.] `[I]n the absence of any unconstitutional statute or rule, it is plaintiffs' burden to articulate a factual basis that demonstrates considerably more proof than a single incident.'" (Beswick v. City of Philadelphia (E.D.Penn. 2001) 185 F.Supp.2d 418, 427.)