A senior woman is found dead in her own blood-splattered apartment in a retirement community. Another case involves a body found inside an abandoned house used for cooking up recreational drugs.

A man is found dead, lying face down, gagged, the four limbs tied to the bedposts, with signs of sexual assault. The house shows no signs of break in.

A man is murdered at a peep show, and the suspects include his cousin, the stripper, her husband, and an ape.

A drugs transport to incineration is attacked by a well-armed gang, but a woman shouting for help for her baby rather distracts Horatio and Speed, whose gun is jammed, but a bullet-proof vest saves his life. Only SWAT sergeant Hollis is killed, but as ballistics later establishes from a distant spot. Horatio finds the woman isn't the baby's mother, she was hired by a drugs gang. CSI is suspected of tipping them off, especially after Calleigh tests positive for cocaine, but Horatio traces that to a nearby spot suitable for the sniper. The fiends even left one of their own, badly wounded Lester Cassidy, behind to die in Paul Tomassi's workshop after consulting suspended MD Guillermo Santoyo.

The murder of a woman at a posh hotel has ties to the drug cartel, a bank robbery, and the witness protection program.