(ABCNews) - The limousine driver whose four passengers were killed in a crash in New York's Long Island wine country has been indicted on criminally negligent homicide and other charges, prosecutors said Wednesday.

Carlos Pino, 58, pleaded not guilty Wednesday in state Supreme Court in Central Islip on an indictment that also charges him with assault, reckless driving and several traffic infractions. His bail was set at $50,000. The driver whose pickup truck collided with the limo, Steven Romeo, was charged with drunken driving offenses. He was released without bail.

The grand jury declined to indict Romeo on more severe charges, said Suffolk County District Attorney Thomas Spota.

"Romeo can be held criminally responsible for driving while intoxicated, but he cannot be held criminally responsible for the crash," Spota said. "The person who is criminally responsible for the crash is Carlos Pino and Carlos Pino alone."

Authorities say the limousine was attempting to make a U-turn at an intersection along Route 48 in Cutchogue, after leaving a nearby winery, when the pickup truck broadsided the limo July 18, 2015. Brittany M. Schulman, 23, of Smithtown; Lauren Baruch, 24, also of Smithtown; Stephanie Belli, 23, of Kings Park; and Amy R. Grabina, 23, of Commack, were killed. Four other women and the limo driver were hospitalized after the collision.

Prosecutors say Pino's vision was blocked by a Jeep that was turning in front of him.

Investigators located five additional witnesses who saw the crash, and an accident investigation found it would be impossible for Romeo to have avoided the collision, Spota said.

"Pino failed to take any precaution or action to make sure he could safely enter the westbound traffic lanes; he continued to attempt his U-turn without stopping," Spota said.

Pino's attorney, Brendan Ahern, called the crash an unspeakable tragedy.

"Our hearts and prayers remain with the families of the young women who lost their lives and were seriously injured," he said. "However, experience tells me that criminal liability cannot, and should not always be measured by the depth of human tragedy."