|Original Airdate||November 17, 2000|
Blood Drops is the seventh episode of season one of CSI:Crime Scene Investigation.
When four members of a family are brutally murdered in a suburban house, except the two daughters who are the sole survivors, the nightshift is called. At first, Gil Grissom and his entire team suspect a bizarre cult murder, but the evidence tells an even more disturbing story, when they discover the motive behind the massacre.
The CSIs arrive at a family residence, a scene of mass murder. Four people of a family of six have been brutally stabbed. Mr. Collins is found in the second floor corridor, Mrs. Collins in her bed, and their two sons in their room.
Grissom questions Tina, the teenage daughter who escaped the massacre. He then talks to Brenda, the younger sister, but she does not say anything until Grissom asks if anyone went into her room. She quietly answers, "the buffalo", but does not say anything else. Grissom notes that a knife - presumably the murder weapon - is missing from the knife block in the kitchen.
The CSIs discuss a possible sequence of events, speculating that the mother was killed first in her sleep and the father ran to protect his children, but was killed on the way to their rooms.
Brass and Grissom question Tina and learn that she has no boyfriend and does not know anyone called “Buffalo”. Grissom processes Tina’s clothing and finds no blood on them.
Sara is assigned to take care of Brenda, who shows signs of emotional shock and trauma. However, she breaks out of her catatonic state when she hears the word "buffalo", becoming hysterical and freaking out. Although Sara thinks that she is not good with children, Brenda attaches herself to her.
Outside, Nick and Warrick find a bidi and a match. They also find tire impressions which match a scooter owned by a boy in the neighborhood. He says that he does not know where his scooter is because he shares it with a few other boys and one of them has it.
Catherine and Grissom question Tina and remind her that she said she hugged her mother's body and tripped over her father's. Tina cannot explain why there is no blood on her pijamas.
The boys who share the scooter are questioned and Jesse Overton admits to having the scooter on the night of the murder but says he does not know where it is. During his interrogation he tries to light a bidi, and when Nick takes his cigarettes and his matches away he notices that two matches are missing from the book. Overton admits to having sex with Tina.
Tina asks Catherine and Grissom if she can see her sister, but is met with accusations that she caught her boyfriend killing her family. Nick matches the match found at the crime scene to Jesse's matchbook. Brass searches Jesse’s garage and finds the scooter and a pair of jeans covered in blood.
Jesse pleads guilty and takes a lie detector test. He admits to each killing and says that he killed them because Tina wanted to be with him and they wouldn't let her. The test shows that he was telling the truth that he had murdered them but lied when it came to the reason.
Grissom goes through the family's effects and finds an amulet on a chain which belonged to Mr. Collins. He cleans the blood off the amulet and discovers a buffalo. He immediately calls Sara and asks her to check Brenda for sexual abuse.
Catherine examines the photographs of the crime scene and tries to put together a timeline. She realizes that the evidence does not fit their theory that the killer murdered the mother first and then killed the father as he tried to save his daughter. The blood drops actually indicate that the father was leaving Brenda’s room, and that the husband was killed first. The killer then went to the mother’s room, dropping blood on the floor from the knife.
Sara discovers that Brenda was being sexually abused, causing Grissom and Brass to interrogate Tina again. Tina reveals that she was also abused by her father as a young girl and that Brenda is actually her daughter as well as half-sister. She killed her father in order to protect Brenda from the same abuse, and had her mother and brothers killed because they never tried to protect her and never even acknowledged how her clothes were getting bigger and that she was pregnant. Tina admits that while she learned to cope with the abuse and accepted it, when she saw her father walk into Brenda's room late at night - enough was enough.
- William Petersen as Gil Grissom
- Marg Helgenberger as Catherine Willows
- Gary Dourdan as Warrick Brown
- George Eads as Nick Stokes
- Jorja Fox as Sara Sidle
- Paul Guilfoyle as Jim Brass
- Timothy Carhart as Eddie Willows
- Robert David Hall as Dr. Al Robbins
- Glenn Morshower as Sheriff Brian Mobley
- Marc Vann as Conrad Ecklie
- Skip O'Brien as Sergeant Ray O'Riley
- Aasif Mandvi as Dr. Leever
- Madison McReynolds as Lindsey Willows
- David Berman as David Phillips (uncredited)
- Eric Szmanda as Greg Sanders (uncredited)
- William Wantland as Extra (uncredited)
- Allison Lange as Tina Collins
- Eric Nenninger as Jesse Overton
- Dakota Fanning as Brenda Collins
- Sean Smith as Ted Goggle
- Del Hunter-White as Connie Bellvue - Family Services Representative
- Jonathan T. Floyd as EMS #1
- Michael Bowman as Oliver (credited as Mike Bowman)
- Paul Raci as Lie Detector Operator
- John Churchill as Shibley
- Tracy Melchior as Reporter
- Morgan Lee Wojnowski as Tina Collins, Age 6
Blood Drops makes reference to the blood droped on the floor by the knife of Collin's killer. The direction of the blood drops indicate the order of the murders. The team later knew why the father was leaving Brenda’s room at midnight.
- This episode is known under three names: it was originally titled The Beast, then aired under the title If These Walls Could Talk, and has been known in all subsequent repeats and home video releases as Blood Drops.