Marc O’Leary: The Serial Rapist Who Terrorized for 3 Years—All Because One Victim Was Ignored

There are cases that disturb because of what was done… and there are cases that haunt because of what could have been stopped. The story of Marc O’Leary sits painfully between both.

Starting in 2008, O’Leary would go on to terrorize women across Washington and Colorado, committing a series of calculated, deeply disturbing assaults. But what makes this case even more chilling is not just the crimes themselves—it’s the fact that his very first victim tried to tell the truth… and no one believed her.

Marc O’Leary was born in 1978 in Colorado. By all outward appearances, his upbringing was ordinary. But internally, something was already forming. According to later investigations, he experienced disturbing fantasies at a very young age—urges tied to control, domination, and violence.

As he grew older, he learned to hide those thoughts.

At first, they surfaced in smaller ways—breaking into homes, watching from the shadows, studying routines. He became a voyeur, quietly building patterns that would later evolve into something far more dangerous.

After high school, O’Leary joined the U.S. Army and was deployed to South Korea. There, he gained discipline, structure, and skills that would later serve him—not in defense, but in planning.

By the time he returned to the United States, the line had already been crossed.

On August 11, 2008, in Lynnwood, Washington, O’Leary attacked his first known victim—an 18-year-old woman known as Marie. He entered her home early in the morning through an unlocked door, something he had already tested before.

He came prepared.

He used items from inside the house—a knife, shoelaces—to restrain her. He blindfolded her, silenced her, and made it clear he had been watching, waiting, studying her life.

Then he assaulted her.

Afterward, he took photos.

It was methodical. Controlled. Planned.

Marie did what victims are told to do—she reported it.

But instead of finding protection, she was met with doubt.

Investigators focused on inconsistencies in her story—details that had been distorted by trauma. They didn’t see fear. They saw confusion. And they misread it.

She was pressured into recanting.

Eventually, she was charged with false reporting.

The case was closed.

And with that, something critical was lost.

Because O’Leary was never identified as a suspect.

Free, and now emboldened, he struck again.

He followed the same pattern—breaking into homes, studying victims in advance, attacking when they were most vulnerable. One of his next victims was a 63-year-old woman in Kirkland.

Still, the cases weren’t linked.

There was no urgency. No pattern recognized.

And so, he continued.

After returning to Colorado and divorcing in 2009, O’Leary escalated. Over the next 15 months, he attacked multiple women across Denver suburbs. His preparation became even more meticulous. He conducted what he called “precombat inspections”—entering homes beforehand to ensure there were no weapons within reach.

He wore gloves. Avoided leaving DNA. Forced victims to shower afterward to eliminate evidence. Took clothing and bedding with him.

He adapted.

He learned.

One victim, a 46-year-old woman, survived by jumping from her bedroom window to escape—breaking ribs and puncturing a lung in the process.

Others weren’t as fortunate.

His victims ranged in age from their twenties to their sixties. And each attack followed the same chilling pattern—control, silence, documentation.

But despite his caution, small details began to surface.

In Colorado, two detectives—Stacy Galbraith and Edna Hendershot—working in different jurisdictions began noticing similarities. Shoe prints. Glove patterns. Behavioral details.

Individually, they were fragments.

Together, they became a pattern.

Surveillance footage captured a white Mazda pickup circling one victim’s apartment. The license plate wasn’t clear—but the vehicle stood out.

Then came a break.

An abandoned white Mazda was reported near another crime scene. It was registered to Marc Patrick O’Leary.

From there, everything began to align.

A patrol camera had already captured his vehicle near a victim’s home shortly after an assault. Witness descriptions matched. Vehicle details matched. Patterns matched.

Investigators obtained a search warrant.

Inside his home, they found what they had been looking for—and more.

Evidence tied to multiple crimes. Tools described by victims. Stolen belongings.

And on his computer, a folder labeled simply: “Girls.”

Inside were hundreds of photographs.

Images of victims.

Proof.

O’Leary was arrested.

Faced with overwhelming evidence, he pleaded guilty to 28 charges in Colorado. In December 2011, he was sentenced to 327 and a half years in prison.

Later, his crimes in Washington were also linked to him. He received an additional 68 and a half years.

Justice, at last.

But not without a cost.

Because by the time he was stopped, at least six women had been attacked—and one had nearly died escaping him.

And all of it traces back to a single moment.

A young woman who told the truth.

And wasn’t believed.

Years later, reviews of that first investigation would call it a “major failure.” Marie had not only been assaulted—she had been failed by the system meant to protect her.

She had been victimized twice.

Today, she has rebuilt her life. But her story remains a reminder of something deeper.

Because this case is not just about one predator.

It’s about what happens when warning signs are missed.

When voices are dismissed.

When the truth is there… but not recognized in time.

And it leaves one question that still lingers—

if someone had listened the first time… how many lives could have been spared?