Minor Character: Las Vegas
Name Peter Arnz
Gender Male
Family Vanessa Arnz (mother; deceased)
Mr. Arnz (father)
City Las Vegas
Occupation High school savant
Hardware store employee
Pathology Murderer
Modus Operandi Charcoal carbon poisoning
No. of Victims 1 killed
1 attempted
Status Incarcerated
Portrayed By Jonathan Tucker
First Appearance Crash & Burn

Peter Arnz is a murderer appearing in Crash & Burn in CSI:Crime Scene Investigation.


Arnz was a gifted science prodigy and an employee at his father's family hardware store with a severe mean streak when obsessed with success and glory. One example being he threatened his teacher's well-being when Arnz got a B in the class. Arnz also had a belief in cosmic and physical workings being more punctual and significant than human element, which left him with a superiority complex even over his parents. He aspired for reaching the ranks of an elite school to work for his degree and career, and he succeeded in getting his acceptance to Princeton. But his parents, Vanessa and Mr. Arnz, refused to pay his tuition, and because his family was financially stable, Peter couldn't apply for financial aid. Finally snapping, he planned to kill both his parents, leaving him the sole beneficiary of his father's hardware store, which he planned to sell for the money for his tuition. He took out the charcoal in his fish tank filter and placed it in the natural gas fireplace in his parents' bedroom. Lying about fixing the chimney damper to keep it in its poor condition, the fireplace burned the charcoal once turned on, trapping the carbon monoxide exhaust in the room and poisoning both parents. Because both parents smoked, Peter hoped their weak lungs would give from the gas and they would die. However, only Vanessa succumbed to the poisoning, as Mr. Arnz quit smoking weeks before the gas sabotage, leaving his lungs healthy enough to circulate the gas through his systems and quickly reduce his carbon levels. He woke up, found Vanessa dead, and called 911, before passing out again from more CO inhalation.

Crash & Burn[]

When the CSIs respond to the crime scene, carbon monoxide poisoning is an immediate giveaway when they see a dead Vanessa pink all over. Peter's statement is that of being asleep during the poisoning, only to be woken up by the medics ringing the front doorbell. He's obviously apathetic to Gil Grissom trying to make a connection with him. Finding out the fireplace is natural gas, the damper's damaged, and the burnt charcoal iis still resting at the bottom, they know soon it's deliberate sabotage poisoning. The mass spectrometer identifies the pure carbon in the charcoal, and the porous consistency reveals charcoal's its form. Going through the possible resources that require it, they also find out the parents are recovering smokers from nicotine levels, but traces of Mr. Arnz's sleeping pills in Vanessa makes him a suspect. Meeting him at his hardware store, Grissom talks with Peter about an Isaac Asimov book he's reading, which Peter elaborates on by confirming his aspirations and skill in science, but they're cut short when Mr. Arnz tells him to unload some more boxes. He's cleared when confesses he drugged his late wife through her ice cream because she hated his work hours, doing it for the second time that night because it work in his job and keep a socially stable household. He mentions Peter was supposed to take care of the damper, being told by him it was back to normal. Grissom goes back into Peter's room, Peter coming up right behind him when ignoring the police tape. Grissom tells Peter how he knows about his outburst against the teacher and just found his fish tank, which Peter drops food into, is missing its charcoal in the filter, leading Peter to be brought into interrogation. Now the prime suspect, Grissom and Nick Stokes play a mild mind game with Peter, getting him to say he didn't fix the chimney because he didn't wanna listen to his "tenth grade education" father, lying to stop being asked. Grissom and Stokes then turn to each other, going through the contemplation of why only Vanessa died in front of Peter. Grissom shocks him with the reveal that his father successfully quit weeks before enacting the plan, pointing out the eventual change in human behavior around him was something Peter was uninterested in. Stokes asks baffled why, with the chances he had, he killed both his parents. Grissom suddenly realizes out loud: Peter couldn't afford getting into college. Peter fully confesses, saying all his dreams were crushed because his parents couldn't pay for him and he couldn't apply for loans or other financial aid successfully. Peter's arrested and incarcerated for murder and attempted murder as a result.

Modus Operandi[]

Arnz left the charcoal from his fish tank filter in the natural gas fireplace. Leaving the chimney damper unfixed, the pure carbon charcoal burned when the fireplace was turn on, turning it into carbon monoxide. With the damper broken, the gas poisoned both of Arnz's both of Arnz parents, anticipating with them both being smokers, they'd die from the poisoning from already having weak lungs. However, Mr. Arnz quit smoking weeks before the poisoning, leaving his lungs healthy enough to circulate the gas out of his systems.

Known Victims[]

  • Vanessa Arnz (poisoned with carbon monoxide from a charcoal-burning trap)
  • Mr. Arnz (poisoned with carbon monoxide from a charcoal-burning trap; survived)