Stephen Brooks (defendant) owned a home equipped with a driveway heater. Exhaust fumes from the heater exited through a vent in the garage. In November 1987, two other home occupants—Jill McDermott and McDermott’s child—became ill from exhaust fumes that had escaped into the house. Brooks called a plumber and an inspector from Vermont Gas Systems (VGS) to examine the system. Both concluded that a bad flap was preventing proper ventilation and that the gas should not be turned on until the flap was repaired. According to the VGS inspector, McDermott was lucky to be alive. Brooks put the house up for sale without repairing the heater or disclosing the defect to the real estate agent. The Cifarelli family purchased the home in July 1988. One night in December, the Cifarellis turned on the driveway heater and put the two Cifarelli children to bed. The next morning, it was discovered that all the Cifarellis except one of the children had died in bed from carbon-monoxide poisoning. Brooks was charged with involuntary manslaughter by reckless endangerment. At trial, Brooks claimed that, because Brooks believed that the heater was fixed when the house had been sold, Brooks did not have the intent required for involuntary manslaughter by reckless endangerment. Several witnesses testified that Brooks knew the heater was defective when Brooks sold the home. Brooks was convicted as charged. On appeal, Brooks argued that the trial court erred in instructing the jury on both recklessness and criminal negligence without distinguishing the intent required by each. Brooks claimed that because recklessness requires a conscious disregard of substantial risk and criminal negligence requires only that a defendant should have known of the risk, the jury might have convicted Brooks under the less-stringent negligence standard.