Several Florida cases in which defendants claimed self-defense have been overturned on appeal because the trial judge incorrectly read to the jury what is sometimes referred to as a forcible-felony jury instruction. According to this particular jury instruction, a defendant may not claim that he acted in self-defense if he did so while "attempting to commit, committing, or escaping after the commission of, a forcible felony."
Suppose a person were to go into a convenience store and point a knife at the clerk while demanding all of the money in the cash register. As the clerk is emptying the register, a customer approaches the robber from behind and hits him on the head with a bottle. The robber then turns around and stabs the customer.
At his trial, the robber would not be allowed to argue that he stabbed the customer in self-defense because the Florida Legislature has decided that a person who is committing a separate and independent forcible felony (in this particular example, the forcible felony of robbery), is not entitled to use deadly force (which Florida law defines as "force likely to cause death or great bodily harm.") That is to say, because the crime of robbery is a separate and independent forcible felony, the trial judge should read to the jury the forcible-felony jury instruction which would result in the defendant not being able to argue to the jury that he stabbed the customer in self-defense.
Where trial judges sometimes get into trouble on appeal is when they read to the jury the forcible-felony jury instruction even though the person on trial is not accused of having committed a separate and independent forcible felony. Perhaps another example from the same Martinez case would help to explain what I mean.
In Martinez, the defendant was charged with committing the two crimes of attempted premeditated murder and aggravated battery with a deadly weapon for the single act of stabbing his girlfriend. At his trial, one of the defenses that Martinez relied upon for both crimes was that of self-defense. However, the trial judge read to the jury the forcible-felony jury instruction even though Martinez was not charged with a separate and independent forcible felony. The result was that the forcible-felony jury instruction essentially negated Martinez' self-defense claim.
On appeal, the Florida Supreme Court ruled that although the trial judge in Martinez' case erred when he read the forcible-felony instruction to the jury, the case would not be reversed because Mr. Martinez' lawyer did not object when the judge read that particular instruction at trial.