Credit: Laramie County Sheriff's Office
On June 9, 2026, Eva Martinez, 57, of Cheyenne, WY, was arrested and has been charged with 1st Degree Homicide in connection with a previously unsolved case from 1988.
On Feb. 28, 1988, Laramie County Sheriff’s Office (LCSO) deputies responded to a call for service at Happy Jack Road and McKinney Drive. An abandoned, unclothed, deceased, newborn baby boy had been discovered near the roadway.
An autopsy concluded that the baby was a fully developed, full-term, 6.5-pound baby. The autopsy found no evidence of significant injury, congenital anomaly, or disease. At autopsy, the pathologist determined the baby had been born alive and was alive for an amount of time due to air being in the baby’s lungs and stomach. The cause and manner of death were undetermined at the time, pending further investigation.
The LCSO followed up on numerous leads and continued investigating the case over the next 38 years as a potential homicide. Continued DNA testing, out-of-state resources, and labs were utilized. All investigative leads and attempts to identify who the baby’s parents were proved unsuccessful. The deceased baby and the case eventually became known as Laramie County Baby John Doe.
In 2021, the LCSO partnered with Othram. Othram's work on the case identified several individuals who were potentially related to Baby John Doe, which helped further the investigation. The investigative leads that Othram helped generate eventually led to the identification and arrest of Eva Martinez, the infant's mother.
The LCSO would like to thank Othram for the investigative assistance they provided with the case. The LCSO would also like to thank the Weld County Sheriff’s Office in Colorado, along with our other law enforcement partners in Tennessee, North Carolina, and Nevada, who assisted us with the investigation.
The Laramie County Coroner’s Office, along with the Wyoming Division of Criminal Investigation’s (DCI) information and analysis team, also played a role in bringing this case to a resolution.
DCI’s crime lab did an exhaustive amount of work on the case over the years. From helping process the scene in 1988, to testing various pieces of evidence and continued DNA testing over the years, the state lab exhausted all available DNA resources they had available at the time with each test. It’s fitting that the Wyoming State Crime Lab performed the final DNA testing that helped complete the case.
Anyone who believes they may have information about this case can contact Detective Sergeant Ryan Martinez at (307) 633-4763.
Republished courtesy of Laramie County Sheriff's Office