The CSI's had a betting pool going to see who would hit a natural death to complete the cycle of a homicide, accidental death, suicide, and a natural death all in one shift.
A man was found dead in the pool of the home he was house sitting for. At first glance his death looked like a burglary gone wrong. Evidence pointed toward a lone shark as a suspect, but after further investigation the CSIs discovered the man had committed suicide. He staged his death to look like a murder so that his ex-wife could collect on his life insurance policy.
A hard core gamer was found dead in his apartment. The autopsy showed he died from choking on his own vomit. The cause of which was first thought to be a seizure brought on by an opponent's online attack, and then murder at the hands of his girlfriend. However, the CSIs found ipecac on the victim's pizza, that mixed with sleeping pills caused the gamer's death. Fingerprints on a pizza box and the bottle of sleeping pills proved that the killer was the ex-lover of the gamer's girlfriend who was jealous of the relationship.
The cycle was completed when David found the new M.E. assistant dead from an aneurysm.