"And should he for some strange reason comply, you would now be liable for anything that may happen to him, your fault or not, and you would be potentially subject to criminal sanctions, should you be unable to produce adequate evidence that he had in fact committed the kind of offense that justifies a citizen's arrest in your jurisdiction." [OldMarksman]
An excellent point. The perp may well be unarmed, and likely deny all wrongdoing.
Its a cruel world, since the time of Jesus, the criminal has had the advantage: he plans, picks his ground, and commits the crimes, and somehow the good citizen must successfully defend himself, all the while avoiding physical and monetary harm.
Thanks for the web referral, I'll check with my police contacts and if there is anything new to report, I shall do.