The Colorado County Sheriff's Office received a call about human remains found near Sandy Creek on Shell Plant Road on July 17, 1976, in Sheridan. This case was initially investigated by Sheriff “Doc” Mueller, Chief Deputy Jim Broussard, Investigator Bill Esterling, and Deputy James Brooks.
Justice of the Peace Pct. 1, Judge Richard Schmidt, arrived and requested an autopsy at the Harris County Medical Examiners' Office. After completion of the autopsy, it was determined the remains belonged to an unidentified female and the manner of death was homicidal violence.
After the case was initially investigated, and with no investigative leads at that time, the case became cold.
The initial report was believed to be destroyed after a flood in the “old Jail” basement, and the investigation was left unknown, and the remains were left at the Harris County Medical Examiner’s Office, seemingly forgotten.
In 2003, Colorado County Judge Al Jamison received a letter from the Harris County Medical Examiner’s Office explaining that the remains were still in their possession and requesting burial.
In September of 2003, Lieutenant Troy Neisner began investigating the case by locating news articles from 1976. Lieutenant Neisner created a new case file and requested assistance from the Texas Department of Public Safety, Ranger Division.
The unidentified female remained unknown and her remains were transferred to the University of North Texas Forensic Anthropology Department. The Sheriff’s Office made countless attempts to identify the female by dental records without success.As the investigation continued, DNA was extracted from the remains and submitted to the CODIS database in 2007. CODIS is an acronym for a combined DNA index system. This computer software program operates local, state, and national databases of DNA profiles from convicted offenders, unsolved crime scene evidence, and missing persons. Unfortunately, the DNA extracted did not match anyone in the system, the case went cold, and the remains were retained at the University of North Texas.
May of 2023, Sheriff’s Investigators met and discussed this case with Sheriff R.H. “Curly” Wied and Chief Deputy Troy Neisner.
It was determined that there was more technology available to Law Enforcement now than there had been since this case originally occurred in the 1970s and even more advancements since first discovering this case in 2003.
Sgt. Justin Lindeman was assigned to take the lead on this case and began contacting organizations to create a genetic genealogy profile of the victim. This is done by utilizing extracted DNA material from the unidentified individual, combined with traditional genealogy methods to create a family tree that will eventually assist in the individual’s identification.
While creating this profile and working on the investigation, Sgt. Lindemann received an email from the University of North Texas Health and Safety Center.
The email concluded that the DNA previously obtained from our unidentified female in 1976 matches the DNA just recently submitted by a representing sibling of a missing person named Isolde Deirdre Yockey.
This DNA match was obtained 47 years to the month after the remains were found.
Sgt. Lindemann, Sgt. Beth Mayfield, and Texas Ranger Cody Rogers met with the sibling in Harris County. She advised that she and her mother have been looking for Isolde since Christmas of 1975.
At the time, Isolde was reported missing in Harris County, but given the circumstances, it was assumed she moved from her residence and left willingly. The sibling informed Investigators that she had recently attended a missing persons event in Harris County in April, which prompted her to provide a sample for comparison.
Since the victim has now been positively identified, and the family, one remaining sister, has been notified, the case remains under investigation into the circumstances surrounding the death.
There are leads being developed at this time, however, the Colorado County Sheriff’s Office is requesting assistance from anyone who might have information regarding this homicide.
Contact Sgt./Investigator Justin Lindemann at 979-732-2388 Ext. 238 or by email at [email protected]. tx.us. You may also contact Colorado County Crime Stoppers at 866-522-8477 (TIPS), or visit www.coloradoso.net, under Crime Stoppers, web tips or text tips.
