Nightline Full Broadcast - Friday, December 26, 2025

The Happy Face Killer & Testosterone Replacement Therapy: A Detailed Summary

Key Concepts:

• Keith Jesperson (The Happy Face Killer): A serial killer who confessed to murdering at least eight women across five states, known for sending taunting letters with happy face drawings to the media.
• Tanya Bennett: Jesperson’s first confirmed victim, whose case was initially misdirected due to a false confession.
• Julie Winningham: Jesperson’s last known victim, whose case led to his eventual capture.
• Pacheo Pass Jane Doe (Paty Skipple): A victim whose identity remained unknown for decades, recently identified through DNA technology.
• Testosterone Replacement Therapy (TRT): A medical treatment used to raise testosterone levels in individuals with clinically low levels, increasingly popular but with potential risks.
• Off-Label Use of TRT: Utilizing TRT for purposes not approved by the FDA, such as performance enhancement or anti-aging.

I. The Happy Face Killer: A Reign of Terror

The segment primarily focuses on Keith Jesperson, dubbed “The Happy Face Killer,” and the impact of his crimes on victims’ families and the investigative process. Jesperson, a longhaul trucker, operated across Washington, Oregon, California, Florida, and Wyoming, preying on women and leaving behind taunting letters signed with happy faces. He confessed to at least eight murders, but the actual number is suspected to be higher.

Jesperson’s modus operandi involved strangulation, often after picking up victims from bars. He described a disturbing lack of remorse, stating he killed Tanya Bennett, his first victim, to cover up an assault. He expressed a fascination with the “scare factor” of potentially getting caught, and a desire to take credit for his crimes, evidenced by his detailed six-page confession sent to The Oregonian newspaper. He stated, “I think these letters were all about his ego and taking credit for these crimes.”

The initial investigation into Tanya Bennett’s murder was complicated by a false confession from Leverne Pavlac, who attempted to protect herself from an abusive boyfriend. Jesperson exploited this, even leaving a message at a rest stop bathroom boasting about his ability to kill again while others took the blame.

II. Capture and Confession

Jesperson’s capture stemmed from the case of Julie Winningham, his longtime girlfriend. After her body was found, police noticed his signature on a receipt in her possession. Detective Buckner’s initial questioning yielded no confession, but Jesperson unexpectedly contacted him via answering machine, stating, “You were right. I want to turn myself in.”

Jesperson ultimately pleaded guilty to multiple life sentences in exchange for avoiding the death penalty. He admitted he likely would have continued killing had he not confessed to Winningham’s murder, stating, “Probably. Yeah.” His daughter, Melissa Moore, grappled with the possibility of a “killer gene” but ultimately concluded that while psychopathic traits may have a genetic component, becoming a serial killer is not predetermined. “So ancestry is not destiny,” she affirmed.

III. Solving a Decades-Old Mystery: The Pacheo Pass Jane Doe

The segment highlights a recent breakthrough in a cold case: the identification of a Jane Doe found in 1993 near Pacheo Pass, California, as Paty Skipple. Investigators had DNA samples from the body and, through advancements in genetic genealogy, matched it to Dawn Benton, whose DNA was submitted through a commercial DNA kit. The confirmation brought closure to Skipple’s family after nearly three decades of uncertainty. Dawn Benton described the moment of realization as profoundly impactful, stating, “Let me get this straight. You didn't just find her. She's now a victim of the Happy Faith killer.”

IV. Testosterone Replacement Therapy: Benefits and Risks

The latter portion of the segment shifts focus to the growing popularity of Testosterone Replacement Therapy (TRT). The global TRT market is projected to reach nearly $500 million in the next four years, fueled by social media promotion and celebrity endorsements.

Dr. Yan Zissas, a physician advocating for responsible TRT use in older adults, emphasizes the potential benefits, including muscle growth, increased energy, and improved libido. However, experts caution that TRT is not a universal solution and should only be administered under medical supervision to individuals with clinically low testosterone levels and associated symptoms.

The FDA and the Endocrine Society warn against “off-label” use for performance enhancement or anti-aging, citing potential side effects such as acne, sleep apnea, high blood pressure, infertility (in men), excess hair growth and voice deepening (in women), and a reduction in the body’s natural testosterone production.

Patient testimonials highlighted the positive impact of TRT when combined with diet and exercise. Sammy Irizari, a stroke survivor, reported increased energy and muscle gain, while Maria Mueller, 60, attributed weight loss and improved well-being to hormone therapy.

V. Concluding Remarks

The segment effectively juxtaposes the chilling story of a serial killer driven by ego and a desire for control with the complex and often-misunderstood world of hormone therapy. Both narratives underscore the importance of responsible medical intervention and the potential consequences of unchecked impulses and misinformation. The resolution of the Pacheo Pass Jane Doe case demonstrates the power of advancements in DNA technology to bring closure to long-standing mysteries, while the TRT segment serves as a cautionary tale about the allure of quick fixes and the necessity of informed medical decisions.