Convicted murderer Gonzalo Lopez reportedly hijacked a prison bus on May 12 near the tiny town of Centerville, halfway between Houston and Dallas.

By the time he was killed by police in a standoff three weeks later, the former Mexican Mafia member had allegedly killed Tomball resident Mark Collins and his four grandsons in what became one of the deadliest prison escapes in American history.

Since his escape and death in a shootout, officials have shared few details about what exactly happened. But an investigation by The Marshall Project and the Houston Chronicle alleges that a series of security lapses preceded the escape.

The news organizations reportedly interviewed half a dozen witnesses on the bus, sources familiar with the police investigation, and obtained previously undisclosed records.

Below are the key findings of the investigation:

  • The prison where Lopez was being held was reportedly understaffed.

Lopez reportedly went on a “significant number” of medical trips in the months before his escape, according to the report. On his numerous trips, Lopez grew familiar with the security protocols of bus rides — and the gaps in the protocols.

Many of those gaps had grown during the pandemic as staff vacancy rates soared to historic highs. By the end of April, a third of prison guard jobs were unfilled statewide.

The vacancy rate of the prison staff at the Hughes Unit, the maximum-security prison where Lopez started his bus ride, was close to 45%, according to the report.

Additionally, though prison policy used to require three officers on every bus ride, officials made the third optional in 2015 amid staffing shortages. So, on the morning of May 12, the driver of the bus, Officer Randy Smith, had Officer Jimmie Brinegar seated at the rear of the bus as his only backup, the report claims.

  • Guards allegedly skipped required strip searches and failed to use metal detectors.

The guards had allegedly grown increasingly lax about some of the most basic functions of their jobs, like letting people out to shower or searching them for contraband, according to the investigation.

On the morning of May 12, Lopez was set to take the three-hour ride from Gatesville to Huntsville, where he had an eye appointment at the Estelle Unit.

When high-security prisoners like Lopez go on a medical trip, policy states they must be strip-searched twice: Once when they leave their cells and again before they board the bus.

But according to four prisoners on the bus that day, that was not what happened. Some claimed they did not have to take off all their clothes, and others told the news organizations that guards did not search them at all.

“That’s how he was able to get on the bus with them knives,” said a prisoner who sat near Lopez on the bus and asked not to be named for fear of retaliation. “He didn’t stash them anywhere weird. They were right there in his pants.”

The claims by the prisoners aboard the bus with Lopez contradict what Bryan Collier, executive director of the Texas Department of Criminal Justice, told state lawmakers at a hearing in June about what happened the day of the escape.

“He leaves the Hughes Unit, goes through two strip searches at the Hughes Unit, and is placed on a transport bus in leg irons and handcuffs,” Collier said.

The prison’s body-scanning chair could also have detected the metal weapons officers missed on Lopez — but, according to the investigation, the guards did not use the metal-detecting scanner that day.

  • Officers reportedly incorrectly identified the escapee as the prisoner seated behind Lopez on the bus.

When Leon County Sheriff’s Office Investigator Victor Smith arrived sometime after 1 p.m., about 30 minutes after Lopez hijacked the bus and escaped, the guards apparently could not tell Smith which prisoner had escaped.

Smith “requested the name of the escapee, but the two guards at the scene could not provide it,” he wrote in a report obtained through a public records request. “The guards at some point provided a ‘travel card’ for inmate Michael Wages and stated that this could be the escaped inmate but could not be sure.”

According to the records, it took prison officials more than an hour to correctly identify Lopez as the escapee.

  • The first police officer on the scene allegedly saw Lopez escaping but did not give chase or take a shot at the fleeing prisoner.

Down the road from where Lopez crashed the hijacked prison bus into a ditch, Melanie Tieperman, 46, reportedly looked on in shock. She was driving her son home on Highway 7 when they spotted the prison bus stuck in a ditch.

She said she pulled over and watched a man in a Texas prison uniform leap from the wrecked vehicle, jump a fence, and start running across an open field, according to the investigation.

As Lopez fled, Tieperman saw a police cruiser parked nearby. Video footage taken by Tieperman’s son apparently shows it was a patrol car from Jewett, an 800-person town with a one-person force run by Chief Sean O’Reilly.

O’Reilly reportedly declined to answer questions.

Reportedly, the officer was on his way home from work when he began chasing after the bus after he heard what had happened. When the prison bus crashed, he was on the scene as Lopez escaped — but Tieperman said he did not shoot at or follow after Lopez.

“The officer did not get out of his car until that inmate was nearly gone,” she told the news organizations. “He didn’t pursue in any way. He did not have a weapon drawn in case any other inmates were to come out.”

Texas prison spokeswoman Amanda Hernandez acknowledged some shortcomings, attributing them to “staff complacency and failure to follow established policies.”

The Texas Department of Public Safety, involved in the search and investigation, declined to comment.