season 4: part 1 sees the return of the csi las vegas team and their nightly quests to process the evidence and unravel the crime, interwoven into this are the subtle and complex relationships the csis share amongst themselves. we welcome back gil grissom (william peterson), head of the team and entomologist, catherine willows (marg helgenberger), single mother with a past and blood spatter expert, nick stokes (george eads) hair and fibre expert, warrick brown (gary dourdan) the audio/visual analyst with a gambling past and sara sidle (jorja fox) the introverted and awkward materials analyst. joining them are lab-man greg sanders (eric szmanda), captain jim brass (paul guilfoyle) and pathologist dr al robbins (robert david hall). with this team on the case trace of evidence is left untouched and no one can fool them.

episode 401 - 'assume nothing'
swinging couples are marked for death in a series of gruesome murders on and off the strip, and even grissom is stumped. meanwhile catherine is devastated when the murder charges against her mentor sam braun are dropped because of her missteps in the case.
featuring commentary from: anthony e zuiker &, carol mendelsohn.

episode 402 - 'all for our country'
with their only suspects dead in the sexual serial killer case, grissom suspects a cop has delivered vigilante-style justice, meanwhile, sara and catherine are called to the scene where a man is found dead and decomposed in a bathtub.

episode 403 - 'homebodies'
the csis work on three cases, two of which may be related - grissom and warrick investigate when a robbery victim is found mummified in a locked and barricaded closet, nick and sara follow up on the report of an unsupervised teen party gone bad, and catherine interviews a five year old who finds a gun that was used in a homicide.
featuring commentary from: naren shanker &, ken fink.

episode 404 - 'feeling the heat'
an infant left in a hot car is found dead, and the csi team thinks that the parents may be guilty of murder. nick and sara investigate the death of a young woman found floating in lake mojave who didn't drown, and an overweight man is found dead in what may be a killer massage chair.
featuring commentary from: anthony e zuiker &, eli talbert.

episode 405 - 'fur and loathing'
grissom and catherine investigate the shooting death of a man dressed as raccoon. meanwhile, nick and sara report to the crime-scene where their stock boy victim is found shot to death, and flash frozen, at a food warehouse.

episode 406 - 'jackpot'
grissom goes solo on a murder investigation that begins with a head being delivered to his office, and ends with his evidence kit being stolen. leaving him with no other choice than to build one from scratch, using common household items to catch a killer in a small town. catherine receives what she thinks is hush money from her father, sam braun.
featuring commentary from: danny cannon &, naren shankar.

episode 407 - 'invisible evidence'
warrick testifies in a rape and murder case where the murder weapon is excluded due to an unlawful search. the judge gives the team 24 hours to find additional evidence or he'll thrown the case out.
featuring commentary from: danny cannon &, josh berman.

episode 408 - 'after the show'
a model and aspiring show girl is missing, and the avalanche of media attention draws out her murderer, a photographer who insists that catherine is the only csi with whom he will cooperate.

episode 409 - 'grissom versus the volcano'
a federal marshal is killed in a car bomb explosion, but he wasn't the intended target. meanwhile, warrick and sara investigate the hot tub death of a famous r&,b singer's wife.

also including these episodes:

episode 410 - 'coming of rage'
episode 411 - 'eleven angry jurors'
episode 412 - 'butterflied'

scene selection