A bought a lottery ticket for $1, and then B stole it from him. Later, it turns out to be a winning ticket for $100 million dollars. If it is beyond reasonable doubt that B stole the ticket (e.g. B admits to stealing it), did B steal $1 or $100 million dollars from A — or some other amount?
I am just a foreign patent attorney who is studying common law to pass the California Bar Exam, but I will present my personal view. (I cannot guarantee the validity of my theory)
There is an equitable theory called Constructive Trust. If it is established, the victim is entitled to benefit of any increase in value of defendant's (thief) property, meaning in this example victim (plaintiff) can recover $100 million.
In order to assert CT, the following must be met:
Wrongful appropriation; Here, D stole lottery ticket. Met.
D has title; Here, D has title to $100 million. Met.
P can trace his property to D's property; P can trace from P's $1 lottery ticket to its possession by D and collection by D of $100 million. Met.
Unjust enrichment by D; D was enriched by stealing P's property (the lottery ticket). Met.
Thus, it is highly possible that a court will order D to hold the property ($100 million) in constructive trust for P. This means, in plain language, that P will recover $100 million.