JEFFERSON COUNTY, Colo. — The driver of a semi-truck that caused a 28-vehicle crash on Interstate 70 last week was formally charged with four counts of vehicular homicide on Friday.

Rogel Lazaro Aguilera-Mederos, 23, from Houston is accused of driving the truck that killed four people in the crash that involved 24 cars and four semitrailers.

He was also charged with six counts of first degree assault and 24 counts of attempted first degree assault.

“They (prosecutors) sent a very clear message — that they believe the person who’s responsible for the deaths of four people and causing the kind of accident he did deserves to go to prison,” said Karen Steinhauser, a former chief prosecutor for the Denver District Attorney’s Office.

She doesn’t believe prosecutors over-charged the case and neither does defense attorney Chris Decker.

“Is it overreaching? No,” Decker told FOX31. “Is it each and every count possibly could apply? Certainly.”

Aguilera-Mederos will be formally advised of his charges Friday morning at 10 a.m.

According to an arrest affidavit, Aguilera-Mederos told investigators that the brakes on the semi failed before the crash and that he was going more than 80 mph at the time of the crash.

Aguilera-Mederos appeared before a judge on Saturday morning for his first advisement where his bond was set at $400,000.

He was taken into custody following the crash on multiple counts of vehicular homicide.

Investigators reviewed a number of videos that appeared to show Aguilera-Mederos out of control, including one filmed by Pedro Olvera. That video appears to show Aguilera-Mederos passing a runaway truck ramp and signs warning truckers about steep grades as the interstate winds into the Denver area.

Another video captured by a YouTuber appeared to show a semi speeding down the shoulder of the interstate moments before the crash happened.

Both lanes of the interstate were closed for several hours following the crash as the Colorado Department of Transportation repaired the highway.