The sixth season begins with Mac’s team recovering from a hail of machine-gun fire aimed at them while they were at a local bar remembering one of their fallen members. One person’s life is significantly changed by the event, and the CSIs become determined to find the shooter.

A killer targets health-care workers. The case turns personal for Mac when the suspect mentions the name of Mac’s father, who died nearly 20 years earlier.

When two bodies are discovered at the North and South ends of the city, Mac and the team deftly begin to navigate the trail of evidence left behind by the killer.

The CSI’s investigate a man’s stabbing, but the wife confesses to the murder. However, the evidence the team has collected doesn’t link to her, but rather to a serial killer whose handiwork is found all across the city.

The CSIs investigate the murder of a rising star that was performing dances in the underground world of hip-hop, and the investigation takes a focus on all the rival dancers.

Hawkes may find himself in trouble after a man dies. The team finally finds out why Hawkes kept asking for overtime.

Which presumably seemed to be a traffic accident, turns out leading to homicide and illegal organ harvesting. The chase of those involved in the slaughter chain makes all three NY, Vegas and Miami CSI teams put their efforts together to put an end to the crimes. Hawkes, in particular, is very upset about the case.

The team has to track down a serial against the clock while frantically looking for Flack, who has gone missing. Mac stands up for him arguing he reported the need tend to a family problem, deliberately misleading Flack’s commanding officer who suspects the real reason behind his strange behaviour..

Mac and the CSIs have uncovered the lair of a murderous madman, also known as The Compass Killer. However, while the Killer is preparing to make a fourth vicitim, the sunrise uncovers one final surprise for the CSIs.

As a consequence of a 911 call, Mac and the team find themselves in a vacant penthouse. However, they discover something else that takes the case into a different direction. Now they have to not only find the caller but also solve the mystery of an unearthed 100 year old corpse as they navigate their way through a booby-trapped house.

A reformed drug addict is discovered dead in an alley, and the evidence suggests that he was murdered. Train appears and performs. Kim Kardashian guest stars

The investigation of a brutal stabbing takes a dangerous turn when it's discovered that evidence at the crime scene was planted, which pits the CSIs against a trusted colleague.

When a beautiful star quarterback of the Lingerie Football League is found murdered in the locker room hot tub with traces of lidocaine in her system, the CSIs are called in to find out who wanted her dead.

A body is discovered in Central Park, drained of blood and missing part of an ear. The CSI's investigation takes them deep in to the underground vampirism subculture. '

A racing legend dies two days before a Grand Prix Race in an explosion in Manhattan. The CSIs find that the car that exploded had been tampered with, and their investigation takes them into the world of racing and beyond. '

On the night of a young man's 21st birthday, his friends take him out to celebrate, but when they turn up dead and he's found walking in the middle of the street covered in his friends' blood and wielding an axe, the CSIs must trace the events of the man's wild night to figure out just what happened.

When a double homicide involving two young journalists who are investigating a story about gold fraud occurs on the eve of St. Patrick's Day, the CSIs must find the clue at the end of the rainbow.

Stella has a hard time convincing the team when a murder that looks like a suicide is being investigated, so Stella does her own investigation into the case.

A death row inmate's final request brings Dr. Hawkes to a Pennsylvania prison and face-to-face with a tragic incident that he has kept secret for many years, just as a prison riot erupts and traps Hawkes inside

When a slab of concrete starts bleeding in midtown, the CSIs' investigation takes them into the underground world of hardcore fighting, where men moonlight as "weekend warriors" for the pleasure of a live viewing audience.

When Mac and Aubrey come across the scene of a 14-year-old boy who has been shot in front of his 12-year-old brother, it takes Mac's drive for justice to another level.

While Mac recuperates at home after being injured, he witnesses a mysterious briefcase exchange that leads to a murder, and unexpectedly brings him in contact with his former girlfriend, Peyton Driscoll

The CSIs follow a trail left by Shane Casey and realize that he is targeting Danny, who is vacationing out of town with Lindsay and their daughter