Cold Case Files: REOPENED – Evidence Kit Sacramento

Podcast: Cold Case Files (A&E / PodcastOne)
Host: Brooke Giddings (narrator), Bill Curtis (classic segment), with primary speakers Investigator Mark Rall, forensic scientist Jeff Herbert, Deputy DA Ann Marie Shubert, and Pat Matringa (victim’s niece)
Date: November 6, 2025
Episode Theme:
This episode revisits the decades-old murder of John Arana in Sacramento, focusing on the long-delayed processing of key forensic evidence, breakthroughs in DNA technology, and the complex path toward justice. It captures the painstaking efforts of investigators, scientists, and family members to bring resolution to one of the thousands of killings that go unsolved each year — highlighting both systemic challenges and rare victories in cold case investigations.

Main Theme & Purpose

The episode centers on the 1992 homicide of John Arana. After his brutal murder, evidence kits languished for over a decade due to backlog and lack of technology. The story follows a Sacramento task force in the early 2000s as they reopen the case with advanced DNA testing, methodically examine new and old evidence, confront heartbreaking dead ends, and ultimately solve the case years later through nationwide DNA matching. The episode illustrates both the limitations and vital importance of evidence kit processing, the doggedness of law enforcement, and the bittersweet nature of delayed justice.

Key Discussion Points & Insights

1. Case Background and Initial Roadblocks

• [01:06–02:11] The murder of John Arana in 1992 left a bloody, chaotic scene. Early DNA technology couldn't analyze the collected evidence, resulting in an 11-year delay before the case kit was processed.
• Backlog Context:
  • Investigator Mark Rall (02:11): "In 2000, Sacramento county receives a state grant to help reduce their backlog of evidence kits."
  • Roughly 600 untested kits waited due to insufficient staff and resources.

2. Task Force Formation and Kit Re-Examination

• [02:51–04:33] Deputy DA Ann Marie Shubert, Investigator Mark Rall, and forensic scientist Jeff Herbert drive the renewed inquiry, selecting John Arana’s murder as a priority.
• Selection Logic:
  • Shubert (03:02): "There’s a lot of victims out there that want to know...they're walking down the street wondering if that’s the person that killed their family member."

3. Crime Scene and Evidence Collection

• [03:16–04:33]
  • Foreign blood throughout Arana's house; potential new DNA suspects.
  • Additional possible evidence: blood swab in the kitchen (sample 38C), a beer can found on the lawn, and evidence of multiple "bleeders" at the scene.

4. Suspect Pool and Motives

• [05:17–06:46]
  • Main suspects were heroin addicts known to the victim; possible motives included robbery or past personal disputes.
  • Pat Matringa (06:02): “My mother owned a house around the corner...my brother lived there. My brother is a heroin addict...and my immediate reaction was somebody from there killed him.”

5. Forensics and DNA Testing

• [07:20–07:57]
  • Blood-stained shirt from a key suspect tested; conventional tests confirm blood, then move to DNA extraction.
  • Jeff Herbert (08:05): "It turns into a nice pink color. It's generally very quick...That's what you would call the classic Takiyama."

6. Emotional Impact and Waiting for Results

• [09:08–09:26]
  • Pat Matringa (09:08): “He was my best friend...whoever killed John needs to pay for it.”
  • Families confront the fear that the killer might be someone close.

7. Outcome of DNA Analysis

• [11:09–15:04]
  • Multiple pieces of evidence yield a full DNA profile — but neither suspect matches. The beer can’s DNA belongs to Arana, not the perpetrator.
  • Jeff Herbert (14:38): “At the first marker, this guy is eliminated as a source...the second suspect, the same thing...he's already eliminated as a source...he's not on the beer can.”
  • Disappointment, but some relief as family members are cleared.

8. Uploading to CODIS and Cold Case Setback

• [16:03–16:43]
  • DNA profile uploaded to national database (CODIS); still, no match.
  • Pat Matringa (16:43): “The person or persons who killed John should not be walking around...I don't think there'll be closure...but justice, they need to be brought to justice.”

9. Breakthrough and Final Resolution

• [17:37–19:55]
  • 2009: A DNA match emerges in Missouri — Michael Peterson, convicted for unrelated burglary, links to the crime scene.
  • No apparent connection between Peterson and Arana, but Peterson’s injuries and affiliations (white supremacist group) align with new evidence from the original scene.
  • Peterson confesses to aspects of the crime, involving another individual (“Terry Cooper”) whom authorities cannot locate.
  • 2013: Peterson is extradited to California and found guilty of Arana’s murder, sentenced to 36 years to life.

Notable Quotes & Memorable Moments

• Ann Marie Shubert (03:02):
  “There’s a lot of victims out there that want to know because they're walking down the street wondering if that's the person that killed their family member...”

• Pat Matringa (06:02):
  “My immediate reaction was somebody from there killed him.”

• Jeff Herbert (08:05):
  “If it's blood, in a short period of time, we should actually see some red crystals form. So there's a good one right there. That's what you would call the classic Takiyama.”

• Ann Marie Shubert (15:34):
  “It’s a perfect example of how sometimes you have your mind set on something and ultimately the evidence proves you… that’s not correct.”

• Pat Matringa (16:43):
  “The person or persons who killed John should not be walking around. We need justice…”

• Narrator (after breakthrough, 17:37):
  “In 2009… a DNA match was discovered. A man named Michael Peterson had been convicted of burglary in Missouri and sent to prison, leading to his DNA being entered into the database.”

Key Timestamps for Important Segments

| Timestamp | Segment | |---------------|-----------------------------------------------------| | 01:06 | Case overview, John Arana’s murder scene | | 02:11 | Sacramento receives grant, backlog explained | | 03:16 | Evidence discussion, selection, and revisiting case | | 05:17 | Suspect profiles and motives | | 07:20 | Laboratory testing of physical evidence | | 09:08 | Family’s emotional toll, personal reflections | | 11:09 | DNA evidence processed after 11 years | | 14:06 | Results: main suspects cleared by DNA | | 16:23 | Profile uploaded to CODIS, no match | | 17:37 | Breakthrough: DNA match with Michael Peterson | | 19:55 | Peterson’s conviction and sentencing |

Episode Tone and Language

The episode maintains a calm, investigative tone, blending the clinical detachment of forensics with the emotional stakes felt by family and law enforcement. Moments of hope and heartbreak are interspersed with detailed explanations of forensic process, all underscored by an enduring commitment to justice.

Closing Thoughts

Cold Case Files: REOPENED – Evidence Kit Sacramento is an incisive look at the slow, often frustrating march toward closure in unsolved murders. It highlights how advances in DNA technology, persistence from dedicated professionals, and the impact on victims' families come together — showing that, with time and tenacity, even cases left cold for decades can be solved.