第 12 季 共 22 集
播出时间：2011年9月22日
第 1 集 73 Seconds
播出时间：2011年9月22日
After multiple attacks on a public tram, the team has just one witness and a lot of questions.
第 2 集 Tell-Tale Hearts
播出时间：2011年9月29日
When three people confess to killing a family, the team must decide who is telling the truth.
第 3 集 Bittersweet
播出时间：2011年10月6日
During a date, Stokes discovers decomposing body parts in part of an art exhibit; D.B. Russell deals with a staff member confrontation.
第 4 集 Maid Man
播出时间：2011年10月13日
The investigators attend the gala grand opening of a mob museum, only to witness an attempted hit on mob lawyer and former mayor Oscar Goodman.
第 5 集 CSI Down
播出时间：2011年10月20日
The CSI unit investigates when Frank, an apparent murder victim, sits up and needs help but is he just another victim?
第 6 集 Freaks & Geeks
播出时间：2011年11月3日
The murder of a popular sideshow performer sends the team behind the scenes at a carnival freak show.
第 7 集 Brain Doe
播出时间：2011年11月10日
The CSI crew is stumped when they discover a disembodied brain at a crime scene where all the other brains are accounted for.
第 8 集 Crime After Crime
播出时间：2011年11月17日
Three new murders related to three unsolved (or incorrectly solved) crimes from the past come back to haunt the CSIs.
第 9 集 Zippered
播出时间：2011年12月8日
The murder of a retired Army Ranger brings the FBI in on the case, to Russell and Catherine's initial chagrin.
第 10 集 Genetic Disorder
播出时间：2011年12月15日
When a man's dead body turns up naked in the bed of Doc Robbins' wife, the detectives try to "just work the scene" without bringing their pre-judgments to the table, but it sure looks like a case of Death During Adultery.
第 11 集 Ms. Willows Regrets... (1)
播出时间：2012年1月19日
Catherine's friend Laura's mogul husband Mark has a lot to hide behind his successful international corporation, and he's hired a crack team of assassins to carry out the murders of anyone who might be aware of what he's doing, and that includes Laura's lawyer and Laura herself.
第 12 集 Willows in the Wind (2)
播出时间：2012年1月26日
The CSI team says goodbye to Catherine Willows as she makes a life-changing decision.
第 13 集 Tressed to Kill
播出时间：2012年2月9日
When a woman is found dead and her hair is done up '70s style complete with vintage clothes, the CSI team discovers clues that point to a killer with a hair fetish.
第 14 集 Seeing Red
播出时间：2012年2月16日
Russell seeks advice from a former colleague during an investigation into the death of a man's ex-girlfriend.
第 15 集 Stealing Home
播出时间：2012年2月23日
When a house is stolen completely off its foundation, the CSIs are on the case in search of answers. Meanwhile, new CSI Julie Finlay showcases her skill in blood analysis.
第 16 集 CSI Unplugged
播出时间：2012年3月1日
When a blackout cripples the city, the CSIs must revert to old-school methods to solve the case of a missing child.
第 17 集 Trends with Benefits
播出时间：2012年3月15日
When a photo of a dead college student starts trending on the Internet, the team steps in to investigate.
第 18 集 Malice in Wonderland
播出时间：2012年3月22日
The team has few leads to go on when investigating a robbery-homicide at a themed wedding
第 19 集 Split Decisions
播出时间：2012年4月5日
When the CSI team is called in to investigate a man who is shot at point-blank range in a local casino, they shut down the entire building to find their killer.
第 20 集 Altered Stakes
播出时间：2012年4月12日
When Stokes learns that a man he helped put in prison is going to have his conviction overturned, the CSI team needs to prove the killer is guilty again or he will be released.
第 21 集 Dune and Gloom
播出时间：2012年5月3日
When a bomb kills an off-road race truck driver mid-race, the CSI team is called on the scene to investigate why.
第 22 集 Homecoming
播出时间：2012年5月10日
Season finale: The investigation of a triple homicide leads to the discovery of corruption running rampant throughout the LVPD. The closer they get to the truth, the more serious are the repercussions. To be continued...
