DNA Links Clark Perry Baldwin to 1990s Interstate Serial Murders

A single male DNA profile extracted from a victim’s pantyhose in Tennessee provided the crucial link to two unsolved Wyoming homicides, bridging a 30-year investigative gap and leading to the 2025 conviction of interstate serial killer Clark Perry Baldwin. The resolution of these cross-country cold cases relied entirely on forensic genetic genealogy (the practice of utilizing DNA databases alongside traditional family tree construction) and the surreptitious collection of abandoned biological material.

On May 2, 2025, a Tennessee jury convicted the 64-year-old former commercial truck driver of the 1991 murders of Pamela Rose Aldridge McCall and her unborn child, sentencing him to life in prison. Though slated for extradition to face additional murder charges in Wyoming, Baldwin suffered a fatal heart attack in custody on July 18, 2025, closing the legal proceedings but cementing a definitive forensic victory.

Biological Evidence Crosses State Lines

The evidentiary trail began with the meticulous preservation of biological evidence across multiple jurisdictions. For decades, the deaths of three women found strangled near major interstates remained isolated inquiries within their respective states.

The first forensic breakthrough occurred in 2012. The Wyoming Division of Criminal Investigation (DCI) analyzed seminal fluid recovered from two unidentified victims—then known only as “Bitter Creek Betty” and “Sheridan County Jane Doe.” Laboratory analysts extracted an unknown male DNA profile and determined both victims were sexually assaulted by the same perpetrator.

Seven years later, in 2019, investigators in Spring Hill, Tennessee, revisited the 1991 homicide of Pamela Rose Aldridge McCall. Forensics experts extracted a male DNA profile from McCall’s pantyhose. When uploaded to the Combined DNA Index System (CODIS—the FBI’s national database of DNA profiles from convicted offenders, unsolved crime scene evidence, and missing persons), the Tennessee profile triggered a direct match to the unknown suspect in the two Wyoming homicides. Law enforcement officially had a geographically mobile serial killer.

Overcoming STR Limitations with Forensic Genetic Genealogy

Despite the geographic link, the DNA profile did not match any known offenders in standard law enforcement databases. Prior to the widespread implementation of genetic genealogy, investigators relied solely on Short Tandem Repeat (STR) profiling. STR analysis is highly effective for matching a suspect directly to a database, but it only examines small, localized sections of DNA, making it virtually useless for identifying distant biological relatives.

Investigators pivoted to forensic genetic genealogy. Analysts generated a comprehensive genetic profile utilizing Single Nucleotide Polymorphisms (SNPs—minute variations in DNA sequences used to determine complex familial relationships) and uploaded the data to public consumer genealogy repositories.

By constructing family trees based on shared genetic markers, genealogists traced the suspect’s lineage to Waterloo, Iowa, eventually narrowing the focus to Clark Perry Baldwin.

Covert Collection and DNA Confirmation

To confirm the genealogical hypothesis without alerting the suspect, the FBI and the Iowa Division of Criminal Investigation initiated surreptitious sampling (the covert collection of biological material left behind in public spaces).

In early 2020, federal agents surveilled Baldwin in his hometown of Waterloo. After Baldwin utilized and discarded a shopping cart at a local Walmart, agents swabbed the handle for touch DNA (epithelial cells transferred via skin contact). Investigators simultaneously collected discarded household trash from Baldwin’s residence.

Laboratory analysis confirmed that the DNA profile extracted from the cart handle and trash was a definitive, statistical match to the semen recovered from the three 1990s crime scenes.

Pathology and Victimology

The forensic timeline aligned precisely with Baldwin’s occupational history as a long-haul commercial truck driver, which provided him routine access to the interstate corridors where the victims were discovered. Post-mortem examinations across both states established a clear modus operandi, with medical examiners determining the cause of death for all three victims as asphyxiation via manual or ligature strangulation.

• Pamela Rose Aldridge McCall: The 32-year-old was found strangled on March 10, 1991, along Interstate 65 near Spring Hill, Tennessee. Autopsy reports confirmed she was five months pregnant.
• Irene Vasquez: Previously classified as “Bitter Creek Betty,” Vasquez was located on March 1, 1992, at a rest stop along Interstate 80 in Sweetwater County, Wyoming. Pathology reports confirmed sexual assault, blunt force trauma, and strangulation.
• Cindi Arleen Estrada: Formerly “Sheridan County Jane Doe,” Estrada was discovered in a ditch off Interstate 90 near the Wyoming-Montana border in April 1992. Like McCall, pathology reports noted she was three months pregnant at the time of her death.

Judicial Resolution and Suspect Death

A multi-agency operation culminated in Baldwin’s arrest on May 6, 2020, at his Waterloo apartment. Prosecutors in Tennessee proceeded first, utilizing the pantyhose DNA match to secure a guilty verdict on May 2, 2025, for the murders of McCall and her unborn child.

While Wyoming authorities prepared to extradite Baldwin to stand trial for the murders of Vasquez and Estrada, the medical timeline superseded the legal one. Baldwin died of a heart attack while detained in a Tennessee medical facility on July 18, 2025.

While the suspect’s death preempted the Wyoming trials, the definitive DNA evidence successfully resolved the identities of two long-standing Jane Does and closed a tri-state investigation that had eluded traditional law enforcement methodology for nearly three decades.

The Evidence

• Crime Scene DNA: Seminal fluid and cellular material recovered from a 1991 Tennessee crime scene and two 1992 Wyoming crime scenes yielded a matching unknown male DNA profile.
• Genealogical Link: Single Nucleotide Polymorphism (SNP) analysis of the crime scene DNA, cross-referenced with public genealogy databases, isolated the suspect’s family lineage to Iowa.
• Confirmation Sample: Touch DNA covertly swabbed from a Walmart shopping cart handle in Waterloo, Iowa, generated a direct microscopic match to the tri-state suspect profile.
• Pathology Correlation: Autopsies established a consistent modus operandi of sexual assault and strangulation, with two of the three victims confirmed to be pregnant at the time of death.
• Geographic Correlation: The victim disposal sites (I-65, I-80, I-90) aligned chronologically with Baldwin’s documented travel routes as a commercial truck driver.