RIO GRANDE VALLEY, TEXAS — For seven years, the disappearance of Colby Martinez haunted the sunbaked streets of this South Texas border town. A dedicated USPS driver, Colby left for her Saturday route in November 1997 and never returned, vanishing without a trace. Her case became one of the Rio Grande Valley’s most persistent mysteries—a cold file gathering dust, a sister’s life paused in grief, and a community left with nothing but questions.
But in the summer of 2004, a routine city project—draining the long-neglected North Canal—unearthed a clue that would shatter years of silence, reignite an investigation, and ultimately reveal a truth more chilling than anyone could have imagined.
A Morning Like Any Other
On the morning of her disappearance, Colby Martinez was a picture of routine. She adjusted her USPS cap, clipped her route sheet to the dashboard, and rolled out of the depot, waving to her younger sister Irene, who was also a part-time postal worker. The sisters, orphaned in their teens, had become inseparable—sharing a modest family home, dreams of better careers, and the daily rhythms of small-town life.
Colby, however, was on the verge of something bigger: two semesters away from a nursing degree, a baby on the way with her boyfriend Robbie Delgado, and plans for a new life. “She was so happy that morning,” Irene recalls. “She was talking about the future, about the baby. It felt like everything was finally coming together.”
But by nightfall, Colby was gone.
The Vanishing
When Colby didn’t return home that evening, Irene’s worry quickly turned to panic. The USPS truck was found abandoned at the edge of her route, keys still inside, mail undelivered. Police scoured the area, but there were no witnesses, no signs of struggle, and—most damningly—no body.
The investigation soon stalled. “It was like she vanished into thin air,” says Detective Ray Ooa, who led the original case. “We had nothing. No evidence, no suspects, just a missing person and a family destroyed.”
Irene dropped out of college, taking a full-time postal position to keep the lights on and the memories at bay. “Every day, I hoped for a call. Every day, I checked the mailbox, thinking maybe Colby would send a sign.”
But as years passed, hope faded, and Colby’s case became another unsolved mystery in a town that had seen too many.
The Canal Yields a Secret
In July 2004, the city began draining the North Canal for long-overdue maintenance. As the water receded, a city worker spotted something blue half-buried in the mud near the Expressway 83 overpass—a battered USPS bicycle, the kind Colby used on her route.
Detective Ooa was called to the scene. “The second I saw that bike, I knew we might finally have a break,” he says.
Forensic teams combed the canal, but years of water exposure had washed away any fingerprints or DNA. Still, the bike was unmistakable—Colby’s mail baskets, her route number stenciled on the frame, the faded USPS logo. It was the first real clue since her disappearance.
Irene was devastated. “Seeing that bike, it was like losing her all over again. But at least it meant someone remembered.”
A New Investigation
The canal discovery breathed new life into the cold case. Detectives re-examined the original files, combed through Colby’s last known deliveries, and tracked down her boyfriend, Robbie Delgado, who had since tried to move on with his life.
But the real breakthrough came from an unexpected source: the city’s traffic department. A technician, tasked with digitizing old surveillance footage, found grainy tapes from a camera at Vine Street and Industrial Boulevard—the intersection where Colby was last seen.
The footage showed Colby, in her USPS uniform, walking her bicycle into a multi-story apartment building. Hours later, a hooded figure—taller, with long dark hair—emerged, pushing the same bicycle. The figure dumped the bike in the canal, then disappeared into the night.
Detectives traced the building’s records and found a name: Josephine Miller, a resident since 1997. The investigation now had a face, if not yet a motive.
The Woman in the Shadows
Josephine Miller had lived quietly in the Rio Grande Valley for years. To neighbors, she was unremarkable—polite, private, with a string of short-term jobs and a new boyfriend, Robbie Delgado. But as police dug deeper, a disturbing pattern emerged.
Josephine had recently cut her waist-length hair short. She was pregnant, moving in with Robbie, and—crucially—had asked Irene to mail a box to her mother in Colorado. The sender’s address: 4782 Industrial Boulevard—the same building Colby entered before vanishing.
When police questioned the building’s manager, Dolores Ramirez, the story began to unravel. Dolores broke down, admitting she had helped Josephine cover up Colby’s murder years earlier. “She was like a daughter to me,” Dolores confessed. “I couldn’t lose her. I helped her hide what she’d done.”
According to Dolores, Josephine had lured Colby to her apartment under the pretense of a package pickup, then killed her in a fit of jealousy over Robbie. Together, they disposed of the body—first in a remote mountain grave, later exhumed and kept in a ceramic urn in Josephine’s closet.
A Chilling Discovery
When police searched Josephine’s apartment and the suspicious package Irene had been asked to mail, they found Colby’s uniform, mailbag, and the urn containing her remains. The evidence was overwhelming.
Josephine, confronted with the truth, attempted suicide but survived. Robbie, drugged and left unconscious in Irene’s home, was revived by paramedics. Both were taken into custody.
Detective Ooa reflects on the case’s grim resolution. “It was obsession, pure and simple. Josephine couldn’t let go. She took everything from Colby—her life, her future, even her memory.”
Aftermath and Justice
For Irene, the answers brought little comfort. “I spent seven years hoping my sister would come home. Now I know she never will. But at least I can bury her, say goodbye.”
Josephine Miller and Dolores Ramirez now face charges of murder, obstruction of justice, and abuse of a corpse. The community, rocked by the revelations, has rallied around the Martinez family, raising funds for Colby’s burial and a memorial at the USPS depot.
Detective Ooa credits Irene’s persistence for breaking the case. “She never gave up. She kept asking questions, kept pushing. Without her, Colby would still be missing.”
A Town Remembers
As the sun sets over the Rio Grande Valley, the canal flows quietly again. But for those who remember Colby Martinez, the truth uncovered after seven long years is a bittersweet ending.
“I want people to remember her,” Irene says. “Not for how she died, but for how she lived—kind, hardworking, always dreaming of something better. She deserved so much more.”
The city now plans to dedicate a bench along the canal in Colby’s memory—a place for reflection, a reminder that even the deepest mysteries can find light, and that the truth, however painful, must always come to the surface.
