Reversal was required where setting fire to a motor home was not “arson of an inhabited structure.” Following an argument with his girlfriend, Goolsby used a vehicle to push an inoperable motor home next to the one in which he was living and in which his girlfriend was sleeping. He then set fire to it. The girlfriend escaped, but the fire spread to the home in which she had been sleeping, destroying both. A jury found Goolsby guilty of arson of an inhabited structure in violation of Penal Code section 451, subdivision (b) and was sentenced to 25 years to life under “Three Strikes.” On appeal, Goolsby contended that the evidence was insufficient to show that the motor home in which he and girlfriend were then living was a “structure.” The appellate court agreed and reversed. The motor home at issue is not a structure as that term is defined in the arson statutes. The court also held that because the only other crime on which the trial court instructed was arson of property, which is not a lesser included offense, the court could not exercise its authority under section 1181, subdivision 6, to reduce the conviction to that offense. Further, remand and a subsequent trial would constitute a new prosecution of the defendant based on the same evidence to prosecute the original charge, and is therefore prohibited. The prosecution failed to prove its case against Goolsby, and the only option is reversal with instructions to the trial court to dismiss the charges.