The tenth anniversary of 9/11 proves a wrenching but clarifying passage for Mac, who, on that day, suffered the terrible loss of his wife Claire Taylor}}. Mac reconnects with former NYFD member Joe Vincent}}, who lost his son on 9/11, to convince him to make a commemorative appearance at the Brooklyn Wall of Remembrance. The Crime Lab investigation of an open-and-shut robbery/homicide proves more complicated than the team had anticipated when Devon Hargrove's}} witness statement is called into q
When an awkward teen is found dead, the team discovers that his efforts to win a sexy punk rock chick's heart may have gone a step too far. Aly Michalka guest-stars.
When the body of a young woman is found in a stolen Ferrari, the investigation leads to a family of car thieves being targeted by a cold and calculating serial killer named Dominik Janos, who's desperate to find what was stolen from him and is willing to kill anyone standing in his way. Now on a race against time, the CSIs must find Janos and the car before the rest of the family meets their demise at his hands.
A night out for a friendly drink takes an unexpected turn when Danny and his rookie cops are caught up in a shooting.
CSIs investigate Hank Frazier,}} the recently paroled brother of young basketball prodigy Riley Frazier,}} after the murder of Hank's girlfriend, Angela Kelly. They must determine if he is guilty or being set up by Riley's coach, Dwight Gavin.}}
The CSIs investigate when a fraternity prank goes awry on Halloween and a pledge master is left for dead in an open grave.
News of a high school house party goes viral but it ends in disaster when a balcony full of teenagers collapses from overcrowding, injuring the teens and killing a girl. During their investigations they uncover more than they had expected and the CSIs must use social media to uncover the truth about how she died. Meanwhile, Jo's final case at the FBI returns to haunt her when the suspect comes to New York and claims another victim.
As the CSIs investigate the assassination of a judge, Jo comes face-to-face with a criminal from her past.
The death of an important witness will lead Jo to a dangerous investigation of a suspected rapist who was freed on her watch in Washington D.C.
The death of a rising boxer and the confessions of a drunken boy leads the CSI to a mysterious stalker.
A home-invasion robbery turned wrong when a real-estate mogul was killed. But it seems like his murder was linked with a plan on a social networking profile.
The CSIs investigate when a role-playing game turns lethal, with one player falling victim to a bona fide killer and the other kidnapped and held for ransom.
When the CSIs investigate two seemingly unrelated deaths, their separate trails of evidence lead to a surprisingly connected conclusion.
The Crime Lab day shift must solve the murder of night shift CSI Lab Technichian Jessica Drake, which mirrors the 1957 cold case murder of Lana Gregory. Suspects include fellow night shift CSIs Harlan Porter,}} and Kim Barnett.}} Former NYPD Det. Paul Burton,}} who investigated Lana's murder provides Mac a vital clue; the color of Lana's lipstick, Stormy Red, which did not show in his original black and white crime photos. Mac becomes romantically involved with his former patrol partner's sister
The CSIs find themselves immersed in the world of competitive video gaming when they discover a murder may be related to a high-stakes tournament.
The team is surprised by an explosion after a wave of brutality threatens a small New York City community when a body is found dismembered and strategically left out on four street corners.
The CSIs are called to a Brooklyn housing project to investigate the murder of a successful businessman who still felt the pull of his old neighborhood.
When Mac is shot during a robbery gone wrong, he finds himself in limbo between life and death. As he fights for his life, the team struggles to keep their emotions in check as they process the evidence and bring the shooter to justice.