As a trucker, Gregorio Salinas-Moore knows the hazards of driving large trucks through the Colorado mountains, and he experienced last week how dangerous it can be when things go wrong.

He was idling in a traffic jam under an Interstate 70 bridge near Colorado Mills Parkway on April 25 when a runaway semitruck slammed into his semitrailer at frightening speed.

Three seconds after Salinas-Moore stumbled out of his semitrailer, it burst into flames. Even worse, his friend Miguel Angel Lamas-Arellano, who happened to be in his car a few feet ahead, was killed along with three other men.

Salinas-Moore attended his friend’s funeral Friday, the same day Rogel Lazaro Aguilera-Mederos, the driver at the center of the deadly crash, was charged with 36 felonies, a traffic misdemeanor and three sentence enhancers that could add prison time on any convictions. The charges include four counts of vehicular homicide, six counts of first-degree assault and 24 counts of attempted first-degree assault.

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Salinas-Moore has serious back pain from the crash’s impact, and he can’t work. But he’s more worried about Lamas-Arellano’s family. He misses his friend, who he last saw on St. Patrick’s Day, and his happy disposition. Lamas-Arellano was 24.

The driver, Salinas-Moore said, needs to take responsibility for his actions.

“There were so many opportunities he didn’t take,” Salinas-Moore said, referring to the driver’s decision to bypass a runaway truck ramp. “He was selfish.”

Aguilera-Mederos was advised of the charges during a 10 a.m. hearing in district court. He appeared on video from the Jefferson County Jail, where he has been held on a $400,000 bond since his April 26 arrest.

In announcing the charges at a Friday morning news conference, First Judicial District Attorney Peter Weir said Aguilera-Mederos will be prosecuted under an extreme indifference theory, meaning Weir’s team believes the driver was so reckless in his actions that he showed no regard for human life.

Aguilera-Mederos’ attorney, Rob Corry, said after Friday’s hearing that the 40 charges represent “massive prosecutorial duplicative overreach.” The truck had a mechanical malfunction and the crash was an accident, he previously has said.

“I can’t understand it,” Corry said, referring to the first-degree assault charges. “I hope we can persuade the court to take attention of this duplicativeness, this inconsistency, and narrow down this case.”

Aguilera-Mederos, a Texas resident, faces decades in prison, even though he was not under the influence or believed to have intentionally caused the fiery crash. Under Colorado law, prosecutors only have to prove that Aguilera-Mederos acted recklessly.

Aguilera-Mederos’s next court hearing is scheduled for July 11.

Lakewood police have said Aguilera-Mederos was going 85 miles per hour when he slammed into stopped vehicles near Colorado Mills Parkway after passing multiple runaway truck ramp signs as he descended from the high country. He allegedly told police from a hospital after the crash that his brakes failed, and he didn’t want to exit the highway for fear of rolling his semitrailer, according to his arrest affidavit.

During his news conference, Weir said the semitrailer was destroyed in the crash and that investigators cannot do a mechanical inspection of it.

In addition to Lamas-Arellano, three others were killed: Doyle Harrison, 61, of Hudson; William Bailey, 67, of Arvada; and Stanley Politano, 69, of Arvada. Six others were treated at hospitals for their injuries.

Aguilera-Mederos gave his first public comments this week in a Facebook message posted by his wife. He expressed his gratitude to all his supporters, adding that “this is not fair what they are doing to me.”

In a Facebook message after the charges were announced, Aguilera-Mederos’ wife wrote in Spanish, “My god, this is killing me … this has made me realize your life can change in a matter of seconds.”

Safety records show Castellano 03 Trucking LLC, a Houston-based company that employs Aguilera-Mederos, has incurred multiple vehicle maintenance violations over the past 24 months, including 10 violations on brakes or brake systems.

Staff writer Kirk Mitchell contributed to this report.