Melissa Casias Missing: What Really Happened on June 26th in Taos, New Mexico?

A Mother Vanishes in Broad Daylight

On Thursday, June 26, 2025, 53-year-old Melissa Casias dropped off lunch for her daughter Sierra at the John Dunn Shops in Taos, New Mexico. Surveillance footage places her there at 12:57 p.m. By 1:38 p.m., her phone had been factory reset. She has not been seen since.

Melissa didn't take her purse. She didn't take her wallet, her ID, her debit cards, or the keys to her Volkswagen Jetta, which was still parked in the driveway. Both of her personal phones were left behind, wiped completely clean of every photo, text, and contact. The only thing missing from Melissa Casias's life that day was Melissa herself.

This is the case at the center of What Melissa Left, a five-part investigative series from Weird True Crime, hosted by Gina and Amber. Episode 1, "June 26th," lays the foundation for everything that follows.

Who Was Melissa Casias?

Before diving into the disappearance itself, it's worth understanding who Melissa was. She was an avid reader who collected every book from authors she loved. She was a plant enthusiast who grew unusual pink and peach poppies. She was a thyroid cancer survivor who depended on daily medication just to function. And she was a devoted mother to her daughter Sierra, whom she had cared for around the clock after Sierra was involved in a traumatic accident.

At the time she disappeared, Melissa worked as an administrative assistant at Los Alamos National Laboratory. She had recently lost her security clearance and was reportedly planning to leave her husband, Mark Casias, looking at apartments in Albuquerque where she and Sierra could live together.

None of this reads like the life of a woman preparing to disappear. She had PTO scheduled to help her mother recover from knee surgery. She had a lake trip planned for the weekend. She had hunting trips booked for the fall. A new job offer was waiting for her, one she never got to hear about.

The Morning of June 26th: Conflicting Accounts

According to Melissa's husband, Mark, the couple had been fighting that morning after he caught her hiding a vape pen. He says Melissa forgot her work badge, decided to work from home, and told him to find his own way home. But records show Melissa had badged into LANL consistently in the days before her disappearance, while Mark's badge hadn't been scanned since June 23rd. Investigators were never able to independently verify how — or whether — Mark actually got to work that day.

Surveillance footage also contradicts parts of Mark's account, including a stop he claimed they made at a gas station that morning. License plate readers that had captured Melissa's car on the same route every single weekday since January never picked it up on June 26th.

The Afternoon: A Scream, a Wiped Phone, and Blood

After Melissa dropped off Sierra's lunch, she was never confirmed on camera again. Her last text to Sierra went out at 1:33 p.m. Minutes later, her phone was disconnected from iCloud and reset. By late afternoon, Sierra came home to find her mother gone, but everything else, purse, keys, wallet, phones, still there.

Within hours, investigators found a red stain near a fish tank in the master bedroom that tested presumptive positive for blood. A pair of boots with fresh mud showed up in an otherwise dusty, cobweb-filled closet. And before anyone had asked him a single question about it, Mark told police that if there had been a struggle in the house, "there would have been several items knocked over."

Why This Case Doesn't Add Up

Melissa left behind everything a person needs to survive: money, identification, transportation, and a phone. What she allegedly took, according to Mark, was a curling iron and a toothbrush. She left a cross necklace from her late mother-in-law sitting on a table, an item she reportedly never took off.

Her family doesn't believe she walked away. And the deeper you get into the timeline of June 26th, the harder that theory becomes to support. Listen to the Full Episode

This post covers the highlights, but Episode 2 goes much deeper into the recorded phone calls, the witness who described a man on horseback near the search area, and the full breakdown of the walking-distance timeline that has never sat right with Melissa's family.

Listen to Episode 1: "June 26" now on Weird True Crime, available wherever you get your podcasts.

If you have any information about Melissa Casias's disappearance, please contact:

• New Mexico State Police: (505) 425-6771

• Crime Stoppers (anonymous): (505) 843-STOP | Text ABQCS to 738477

Weird True Crime is an independent true crime podcast. Follow us on Instagram, TikTok, and YouTube @weirdtruecrime, and subscribe on Patreon for bonus content.