--A truck driver involved in the highway crash that critically injured comedian Tracy Morgan and killed one of Morgan's colleagues is accused of vehicular homicide and not sleeping for 24 hours prior to the crash.
Kevin Roper, 35, of Jonesboro, Ga., is accused of slamming a Walmart big rig into Morgan's limo bus early Saturday along the New Jersey Turnpike, police said. The crash killed one man on the limo bus and injured four others, including Morgan, 45.
Morgan's longtime writing partner, James "Jimmy Mack" McNair, 62, died at the scene.
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Roper allegedly "commit[ted] vehicular homicide by operating a vehicle recklessly and caus[ing] the death of James McNair, specifically by operating a 2011 Peterbilt Truck ... on the New Jersey turnpike without having slept for a period in excess of 24 hours resulting in a motor vehicle accident in violation of NJS 2C 11-51, a crime of the second degree," according to a criminal complaint from the Cranbury Township Municipal Court.
The document also accused Roper of multiple counts of assault by auto "and causing serious bodily injury" to Morgan, his assistant, Jeffrey Millea, 36, and Ardie Fuqua Jr., 43, a comedian.
Roper was set to appear in court Wednesday to answer charges against him, according to the complaint. He was free today after posting $50,000 bond.
Morgan, Millea and Fuqua remained in critical condition this morning, a spokesperson for Robert Wood Johnson University Hospital told ABC News. In addition, Harris Stanton, another comedian, was treated and released.
Morgan, the former star of "Saturday Night Live" and "30 Rock," was recovering from a broken leg, femur, nose and several ribs. His rep, Lewis Kay, said Morgan was "more responsive" Sunday.
"We expect him to remain in the hospital for several weeks. His family is tremendously overwhelmed and appreciative of the outpouring of love and support from his fans," Kay said.
The six-vehicle crash happened in the northbound lanes at mile marker 71.5 at around 1 a.m. Saturday, according to New Jersey State Police.
Roper turned himself in after the crash. Walmart has placed him on administrative leave and promised "to take full responsibility" if the accident was caused by the company's driver.
The driver of the limo bus said that after the crash, he heard Morgan screaming.
"I climbed around and heard Tracy screaming for help," said his driver, Tyrone Gale. "I climbed up on the body of the limo bus ... but I couldn't reach them."
Morgan and six others were on their way back to New York from a standup comedy show in Delaware. Sources said the truck swerved to avoid the limo, but instead hit it -- causing the limo to lose control, slam into other cars and overturn.
Since the first hours after the accident, investigators have focused on whether Roper dozed off behind the wheel, because he closed in on Morgan's limo and other slow-moving traffic so quickly and only maneuvered to avoid a crash at the last moment.
In talking to investigators after the crash, police told ABC News, Roper said he had not realized there was a pocket of slow-moving traffic in front of him until it was too late.
The National Transportation Safety Board was investigating the crash along the New Jersey State Police.
Morgan has four children, including a baby daughter with his fiancee, Megan Wollover.
ABC News' Tom Kelly, Michael S. James, Daniel Good and The Associated Press contributed to this report.