"Bait Cars" and formal elements of Larceny

This question concerns law, but it is a general question involving law and not a request for advice with a specific case. No specific jurisdiction is indicated, but I am in the US and am more interested in cases, statutes, or law review articles that apply to Common Law jurisdictions such as the US, UK, and Canada.

One of the essential elements of the Common Law crime of Larceny is lack of consent. That is, if I am OK with you taking something of mine, then if you actually come and take it, you are not guilty of larceny, regardless of your intent at the time you take it.

http://en.wikipedia.org/wiki/Larceny

How does this work with Bait Cars?

http://en.wikipedia.org/wiki/Bait_car

It seems to me, that the very act of a law enforcement agency placing a bait car on a public street is an indication that they, at some level, are interested in someone taking it, which to me seems awfully similar to consent. But, police continue to use this practice, so it must have some effect.

Has any defendant accused of taking a Bait Car ever raised as a defense the fact that the law enforcement agency in question wanted someone to take the car (so the police could bust them) as constituting consent to take the car?

I’m guessing, based on common sense, that this is not a defense, but I don’t have enough legal training to be able to explain why.

The part I bolded is something I don’t think you can assume.

I’m not sure about the common law crime, but at least in my state the “consent” language is not in our theft statute so it would definitely not be a problem here. I suspect this is also the case in a lot of other states.

Why not? I do understand that cops believe that just having bait cars out (and advertising such) is at least a minimal deterrent, but without actual arrests being made, perps don’t know if it’s a bluff and I would think that the police do want to reduce the number of auto thieves and wannabe auto thieves in the neighborhood by setting up a sting operation to grab a few off the street and teach them a lesson.

“Consent” is not what the police are giving.

Their purpose in placing the bait car is to identify and arrest those people that are willing to steal cars. The mere fact that they place a car invitingly in a place that they know has a car theft problem in no way constitutes consent. You say that “at some level” they want people to take the car. That may be, but whatever that “level” is, it doesn’t rise to consent.

If the police were giving their consent to people taking the “bait car”, then presumably when someone took the bait car the police would just watch and shrug and go have another donut. The fact that when someone tries to take the bait car, the cops respond by swooping in and arresting them, would seem to indicate a lack of consent on the part of the police to their car being taken.

Nor does me leaving my door unlocked indicate that I consent to someone entering the vehicle and removing items within it.