Trama

A bloodied toddler walks down a street. Back at her house, her mother and three brothers are found dead. The only other survivor is her father who has a gunshot wound on his back.

Blood-covered toddler Erin Caplin's wandering is backtracked to the extremely untidy parental home. Neither neglecting mother nor her three siblings survived the gunshot, not even athletic teenager Luke, who cared for the other kids more than the parents, only father Jason Caplin pulls through after surgery. The mess and autopsy confirm unhealthy neglect. The team soon suspects a domestic drama.—KGF Vissers

Season 1 Episode 8 - Slaughterhouse A toddler wanders down a suburban sidewalk with obvious blood-soaked pajamas. Horatio pulls up to where the little girl was found, asking Detective Sevilla, What have you got? The detective says the child was spotted by a neighborhood gardener as she was walking down the sidewalk. Horatio asks the paramedic What have you got? The paramedic answers, there's not a mark on her. Horatio responds, my guess is someone close to this child is either dead or dying.

Processing begins with the child, as Speed works with Horatio swabbing the little girl. The pajamas are bagged for trace-processing. Horatio mentions to Sevilla the sunburn on the child is on one side of her face, indicating her line was a straight line North. Horatio searches the neighborhood for a starting point of the toddler, while processing begins with the pajamas having Megan cutting in pieces and dispensing them. Speed and Calleigh ask if they found out where the child was to start, then Speed recognizes something on the stained pajama foot, and leaves to examine it more carefully. Megan and Calleigh process blood DNA, three for three male blood types on the child. The child picked up soil with grass-killer-chemicals on her pajama-feet, indicative of an area where it has been recently re-sodded. They are looking for a house with recent re-sodding, Delko is in a copter helping search for the house. Calleigh calls Horatio with a revision, there are four different DNA's all related to the little girl.

Det. Sevilla and Horatio find the house with a blood trail down the front walk, entering with guns drawn, finding dead bodies in the house. Horatio finds a surviving male, the shot man saying his son did this. Horatio summons an ambulance for the surviving father. Horatio hears something, asking Sevilla it's origin, when they find another shot male at a bedroom-computer-desk. Horatio enters an unkempt kitchen, dirty dishes everywhere. Horatio heard the beep of the microwave oven, opening it, he sees a baby bottle. Speed meets Horatio just outside the house, body count five, one surviving and being wheeled by paramedics to the waiting ambulance. Current family member status is father was brought to the hospital, toddler is at social services, and a shotgun is found, the likely murder weapon, left on the floor with spent cartridges.

Processing begins outside by Delko while Calleigh enters the house. Det. Sevilla provides the identification of the house members, names, ages, including a newborn. Dad works at a local mall, Mom is stay-at-home, four kids, Luke 16, Tim 9, Erin 17 months and Max 6 weeks. Delko reports no forced entry, sliding glass doors open, Det. Sevilla says Mom was tired with a newborn. Horatio states the toddler belonged home, the Dad didn't, what was the dad doing home.

Alexx states TOD between 8 AM to 1 PM. Mom is the only member not shot in the back and Speed says mom was last to die. Son, headphones in use, back to door, home with a fever, based on TOD temperature being higher than the rest. Calleigh and Delko examine the master bedroom collecting black hairs in the bed and a prescription bottle full of anti-depressants, re-filled three weeks prior. The mother was a blond.

Horatio and Delko are in the kitchen see the empty fridge, the overflowing garbage, the fast-food-bag, dirty dishes all around, a family obviously living on fast food. Horatio notices the fast food bag is full, but one partially eaten fry.

Calleigh and Horatio are in the garage, Dad's keys left in the ignition, garage door closed and gun-safe rubbed with ammonia. The garage had two cars, the station-wagon mom rarely used.

Alexx is providing Horatio data on the dead. Luke, 16, shot twice, shoulder and base of the skull; Luke had gastric ulcer, teeth-enamel worn to second layer from grinding, and he bit his nails; the shotgun spray killed his infant brother lying next to him. Horatio states Lukes wounds signify he was on the move, and Alexx says it would only take a few pellets for the infant to die. Teen-age Luke's stomach contents reveals the half fry, hardly chewed, interrupted by the carnage in the house. Alexx says Luke was a sixteen-year old stress case, possibly due to his home life. Mother's wound is one shot to lower head; no GSR on mother; died instantly; nine year old Tim's wound was immediately fatal as well; one shot dead center, severed his spinal cord.

Sevilla talks to surviving father as he lies in hospital bed. He says he got a call from his wife she was upset the baby wouldn't stop crying. He felt heat in his back. Delko hands Megan a hair sample from the master bed, it is dark hair, Megan says mother was blond. Calleigh dismantles the shotgun for processing, diagramming the murder scenes throughout the house, indicating the victims and how they were shot.

DNA comes back from hair in master bedroom, dark hair traced to sister-mom is blond. Calleigh is fingerprint-fuming the shotgun and baby-bottle. Sevilla interrogates the sister, who is aware the mother was seeing a psychiatrist and on medication. She was in their bed holding her sister for comfort, she accuses husband of hiding at work, while mom was home with four kids. The sister was away on business at the time of the killings. Calleigh says no prints legible on shotgun, nine year old Timmy was warming the baby's bottle.

Speed and Delko are inside trying to find out how the toddler survived. They discover there is a bloody blanket in the doghouse and there is no dog to be found. Horatio and Calleigh re-enact the shooting of the mother on the couch by firing a shotgun into a dummy observing the spatter on the artificial ceiling. Conclusion was her body angle on the couch indicate she was taking a nap. Possible she could have pulled the trigger, but doubtful.

The blood-transfer onto the doghouse-blanket came from Mom---one source per Speed. The blanket did not contain any yard-chemicals per Delko, therefore, someone carried the toddler to the doghouse; that member would have had the yard-chemical on their shoes. The distance from the doghouse to the house entrance was eleven-feet four-inches, too far for the child not to get the chemical on the blanket. Inspecting the shoes to determine who carried the toddler indicates Luke has a trace as does Dad. Whoever carried the toddler into the yard with Mom's blood did so to save the daughter.

The killer was someone still standing after the mother died, only two members eligible, Luke and Dad. The crime is now a murder, not a murder-suicide. Speed asks do you think Luke could have done this? Horatio speculates he is a 16 year old kid with an ulcer; could he get sick of taking care everyone?

Luke brings lunch home to his siblings and walks into a massacre. Luke saves his sister, putting her in the dog house with her blanket, the killer shoots nine year old Tim. Instinctively, Luke picked up his infant-brother, thinking the killer was still in the house.

The key evidence is the gravitational blood-drops on the baby's shirt are from the father. The drops prove the father was standing over the baby when he was shot in the back by Luke. After dad fell from the shot, Luke grabbed the baby heading out the door, the father got up, shot Luke twice while Luke held the baby trying to leave the house.

Horatio and Detective Sevilla confront the father holding his daughter in his driveway. They explain to the father the significance of his blood-transfer to the baby's clothing. Horatio tells the killer exactly what occurred after the transfer where Luke shot him to prevent any more of his murders, only to be gunned down with his infant-brother, trying to escape.

The father is cuffed, put in the squad, saying he could not face them anymore. Horatio says so you shot them in the back. Horatio tells Sevilla the father is setting the groundwork for his defense, two-pronged, I didn't know what I was doing and I certainly didn't know it was wrong. The plea to be insanity, despite killing members of his family, three of four children and his wife.

Ammonia was on the father's shirt which he used to keep his prints off the gun safe. He called home for his wife to check the gun safe to see if he left it open, he came home at 11:45 AM, opened the safe without leaving prints.

Horatio laments to Speed that his surviving daughter will know everything that happened, showing a picture in the paper of the sister holding the daughter.