SAN DIEGO -- A man who was allegedly driving a pickup truck loaded with undocumented Mexican immigrants when it crashed on Interstate 8 last Thursday, killing two women, pleaded not guilty Tuesday to murder charges and other counts.

Carlos Moreno, 20, believed to be from Jalisco, Mexico, was ordered held in lieu of $2 million bail.

Moreno, who made his appearance in a wheelchair via a video arraignment, also denied charges of assault with a deadly weapon, child endangerment and trying to dissuade a witness.

A 2-year-old boy who was riding in the truck with his mother suffered a broken clavicle in the crash. A third woman was also critically injured.

The victims who died were 17 and 59.

U.S. Border Patrol agents began chasing the pickup after it allegedly sped off from the Tecate border crossing, carrying more than a dozen illegal aliens.

"The chase lasted 22 miles," prosecutor Mike Przytulski told Superior Court Judge Louis Hanoian. "There were two attempts to lay down spikes by Border Patrol agents. One of them failed. The other was partially successful."

Authorities said the pickup -- with one flat tire -- crashed through a guardrail on westbound Interstate 8 and plowed head-on into a bridge abutment over state Route 79.

Przytulski told the judge that while Moreno was trapped in the pickup, he told the undocumented immigrants they "better not talk."

The alleged comment was overheard by paramedics, the prosecutor said.

Przytulski unsuccessfully argued that Moreno be held without bail.

"He is a danger to the entire community," Hanoian said. "He is a flight risk, obviously."

Moreno is scheduled to return to court Jan. 24 for a readiness conference. A preliminary hearing is set for Jan. 28.

Co-defendant Anselmo Pedroza Ariz Mendiz, who is in federal custody, is scheduled to be arraigned Jan. 22, Przytulski said.