INDIO, Calif. -

A 29-year-old former Yucca Valley resident pleaded not guilty Friday to gunning down a man next a party bus in Palm Desert more than two years ago -- leaving the man paralyzed -- and threatening a witness.

William Oliver Sumpter Jr. was arrested near Eureka Jan. 12 on a warrant stemming from the summer 2011 shooting. It left Juan Eliasarrars, 35, paralyzed from the chest down and confined to a wheelchair, according to the Riverside County Sheriff's Department.

Sumpter was charged in December with one count each of attempted murder and intimidation of a witness, and entered his not guilty pleas at his arraignment at the Larson Justice Center in Indio.

Riverside Superior Court Judge Graham A. Cribbs kept Sumpter's bail at $1 million, and ordered him back to court for a trial readiness hearing April 29, according to court records.

The shooting was reported shortly after 10 p.m.  on Aug. 26, 2011, near California Avenue and Fred Waring Drive. Eliasarrars, an Indio resident, was targeted while walking to a house party in the area with a 21-year-old La Quinta woman, according to the sheriff's department.

According to a declaration filed in support of an arrest warrant, Eliasarrars said he'd gotten into a fight with Sumpter on a party bus, and was shot at a stop.

A woman on the bus told authorities she saw the fight, ``saw flames come out of the end of a gun, heard gunshot, and saw the suspect walk back onto the bus.''

Eliasarrars was shot four times and said his back was turned when he was attacked. It was unclear how much earlier the fight occurred or when he'd gotten off the bus.

He was initially uncooperative with authorities, but eventually he and others identified Sumpter as the alleged shooter, according to the declaration.

The woman on the bus said Sumpter ``told her she better not snitch and
threatened her life if she did.'' She told an investigator ``she was willing to testify to what she witnessed ... because she felt the person who did this should be held responsible,'' the declaration stated.

The woman who was with Eliasarrars also identified Sumpter as the alleged shooter and said the attack left the victim ``bloody and dying in the street,'' according to the declaration.

Sumpter was arrested near Garberville, in Humboldt County, when deputies made a traffic stop in January and found he was wanted on the Riverside County warrant.

He was booked into a Humboldt County jail in Eureka and brought back to the Coachella Valley.