When Skyler Rocz was promoted to detective, she had been on the job for just six weeks. Few expected her first major assignment to become a defining case—one that would ultimately send a woman to prison for life and expose a disturbing pattern of deception and violence.
Rocz, then 30, was called to a Texas hospital in January 2023 after medical staff raised concerns about a man admitted in a diabetic coma. The patient, Joseph Hartsfield, 46, was unresponsive, and doctors suspected something was wrong. His blood sugar had plummeted, and despite treatment, his condition did not improve.
What initially appeared to be a tragic medical emergency quickly drew Rocz’s attention. Hospital staff believed there may have been an excessive amount of insulin in Joseph Hartsfield’s system—a substance that can be lifesaving for diabetics but lethal when misused, and notoriously difficult to trace as a murder weapon.
The patient’s wife, Sarah Hartsfield, a former U.S. Army sergeant, told authorities she had found her husband unresponsive at home. Rocz soon learned she waited about an hour before calling 911. At the hospital, Rocz observed behavior she later described as inconsistent and unsettling—alternating between casual conversation and brief, performative displays of grief.
Despite these red flags, Rocz encountered skepticism from her superiors. She was told she was pursuing a case that didn’t exist, “beating a dead horse,” as she recalled. But she disagreed and continued digging.
As Rocz examined Joseph Hartsfield’s background, the case expanded dramatically. Family members told her he had been planning to leave his wife and had opened a new bank account without her knowledge. She also learned of troubling incidents from Sarah Hartsfield’s past, including the fatal shooting of a former fiancé in 2018—an act Hartsfield claimed was self-defense—and allegations of a murder-for-hire plot involving two previous husbands. No charges were filed in those earlier cases, and Hartsfield has denied any wrongdoing.
The turning point came when Rocz analyzed Joseph Hartsfield’s cellphone. Messages sent just hours before he was hospitalized raised new questions. From his phone, Joseph had sent Sarah copies of personal documents, including his driver’s license, bank details, a wedding photo, and credentials granting access to his phone data after death.
Using that information, Rocz obtained a warrant for Sarah Hartsfield’s phone. What she found contradicted Sarah’s account of her husband’s final hours. While Sarah told investigators she had been asleep and heavily medicated following surgery, phone data showed she was active on her device nearly every hour. Rocz also discovered deleted internet searches and text messages revealing escalating marital conflict, with Sarah pushing for Joseph to leave the home and end the marriage.
The Harris County Institute of Forensic Sciences later ruled Joseph Hartsfield’s death was caused by complications from the toxic effects of insulin. Although the manner of death was officially undetermined, prosecutors argued that Sarah Hartsfield deliberately administered a fatal dose.
In February 2023, less than a month after Rocz first stepped into the hospital room, a grand jury indicted Sarah Hartsfield on a murder charge. The case went to trial last year, with jurors hearing not only about the insulin evidence but also about Hartsfield’s history of volatile relationships and unexplained violence surrounding former partners.
In October, the jury convicted Sarah Hartsfield of first-degree murder. She was sentenced to life in prison.
For Rocz, now an investigator with the Chambers County District Attorney’s Office, the verdict was both vindication and relief.
“I felt weak in the knees,” she said afterward. “I was just thankful that justice was done.”
What began as her first callout as a detective became a career-defining investigation—one that proved experience isn’t measured by time on the job, but by persistence, judgment, and the willingness to trust your instincts when others doubt you.
