Robert Duane Bush, 68, remained in custody at the Clark County Detention Center on Wednesday morning, according to jail records. He is the president of the Las Vegas chapter of the National Action Network, a civil rights organization founded in 1991 that advocates for equal opportunity and a modern civil rights agenda.

According to a Metropolitan Police Department news release, Bush was driving a 2013 Mercedes E-350 northbound on South Las Vegas Boulevard near 4th Street at 4:51 a.m. Saturday when the car left the roadway, mounted the sidewalk and struck a 29-year-old man who was standing there. The vehicle continued along the sidewalk and collided with a palm tree, coming to rest partially in the roadway and partially on the sidewalk.

The pedestrian was taken to University Medical Center, where he was treated for life-threatening injuries. His name has not been released, and authorities have not provided an update on his condition.

An impaired driving report offers a slightly different account, stating that the pedestrian was crossing Las Vegas Boulevard in a marked crosswalk when he was struck, and that Bush's vehicle then ran off the roadway.

Bush was also treated for injuries at UMC before being booked into the county jail. Police said he admitted to driving the Mercedes and told officers he had just left a cigar bar and was traveling home. According to the report, Bush said he had consumed two glasses of wine at the cigar bar about two hours before driving.

Police reported that Bush had slurred speech and smelled of alcohol. Two blood draws were taken, and a spokeswoman for the Clark County district attorney's office said Thursday that Bush's blood alcohol content was measured at 0.16 and 0.12. Nevada's legal limit is 0.08.

Bush was initially arrested on suspicion of reckless driving and DUI, but court records show prosecutors filed only the DUI charge in a criminal complaint. He has pleaded not guilty and posted a $50,000 surety bond, according to court records.

A police news release listed Bush's address as Laguna Hills, California, while a jail custody record indicates his home is in Las Vegas.

Chief Deputy Public Defender Michael Yohay declined to comment on the charge. The national chapter of the National Action Network did not respond to two inquiries seeking comment this week.

The crash remains under investigation. Anyone with information is urged to contact the Metropolitan Police Department.