Episode 201: Judgment Call Don and Charlie investigate the murder of a judge's wife who was gunned down in her garage. Since she was driving her husband's car, it's unclear whether she was the intended target or her husband, who is currently hearing a death-penalty case involving a local gang leader. As the probe intensifies, Don reconnects with an attractive prosecutor whose life may also be in danger. Math used: scatter plot, Bayesian spam filtering, conditional probability, dark matter, decision theory, pi, quantum entanglement, origami Episode 202: Bettor or Worse A woman gives a Beverly Hills jewelry-store owner a note informing him that his wife and daughter have been kidnapped and will die unless he hands over diamonds worth thousands of dollars. He gives them to her, but then she is gunned down by a security guard. The shooting gets Don involved in the case and he enlists Charlie's help in identifying the dead woman through her car's keyless remote. Math used: cellular automata, Farey sequence, point spread, pseudorandom numbers Episode 203: Obsession A stalker frightens a popular singer in her Hollywood Hills house, but doesn't harm her. The FBI becomes involved when she reveals a series of threatening letters she's received through the mail. Meanwhile, Charlie analyzes the handwriting from the letters and learns that they are from two different people. Later, a photographer is found dead near the singer's house, and Don believes the man was murdered and that his death is connected to the stalking case. Math used: trigonometry, curvelet analysis, forensic information system for handwriting (FISH), spherical trigonometry, art gallery problem Episode 204: Calculated Risk The star witness in a federal stock-fraud case against the CEO of a now bankrupt major corporation is gunned down in her house before she can testify. The victim was the company's chief financial officer and her testimony was likely to bring down the CEO and other corporate executives. The only witness to the murder is the woman's 11-year-old son, who is in shock and is reluctant to talk. Math used: conditional probability, decision tree, compound interest Episode 205: Assassin Don and Charlie try to unravel an assassination plot to be carried out on U.S. soil. They get wind of the plan after a forger is arrested and Charlie decodes a notebook found in the forger's apartment. The investigation leads to the son of a slain Colombian leader. Math used: transposition cipher, game theory, paper plane