Van Exel was released on $25,000 bond, said Executive Chief Deputy Jesse Flores of the Dallas County Sheriff's Department.
Van Exel is charged in the shooting of Bradley Bassey Eyo, 23, in the Dallas suburb of Garland. Eyo's body was dumped near Lake Ray Hubbard, authorities said, and had an apparent gunshot wound to the upper body.
Police found the remains on Sunday and arrested Van Exel on Wednesday, authorities said.
In an interview with CNN affiliate WFAA, Eyo's father said police told him that Van Exel said the shooting was an accident.
"They were playing with a shotgun, and when it went off on Bradley, he didn't know what to do, took his body and dumped it on the street," the father told WFAA.
Authorities told reporters that they reviewed the case closely before making it a capital offense.
"If a person is making the assertion this was an accident -- you place the body in a vehicle and moved it to a second location -- that in itself, coupled with the fact that property is missing, makes this a capital murder," said Deputy Chief Craig Miller.
A cell phone and shoes were the missing property, said Dallas police spokesman Kevin Janse.
Paul Johnson, Van Exel's attorney, told CNN the shooting was the result of "horseplay."
"The young men were involved in a bunch of horseplay. They didn't believe it was loaded and, unfortunately, it was," Johnson said. "Unfortunately, there was a tragic result to the horseplay."
The two men had been friends for years and were neighbors who lived across the street from each other, Johnson said. Van Exel does not live with his father, Johnson said.
"Everybody considered them to be like brothers," the attorney said of the two young men.
When asked why Van Exel allegedly moved the body, Johnson said Van Exel went "into a state of shock and panic."
"When it occurred, there was no question his friend was deceased," Johnson said.
Van Exel tried to call his family, but he "couldn't get a hold of anybody," Johnson said. "You are talking about a 20-year-old boy."
Van Exel and Johnson went to police and cooperated, Johnson said. Van Exel consented to have his home and vehicle searched, Johnson said.
Johnson described the families of the two young men as close. "There has been communication between the families since the incident," Johnson said.
The elder Van Exel became player development instructor for the Atlanta Hawks in September after serving as an assistant coach at Texas Southern University, according to the Hawks' website. Van Exel, 39, played 13 seasons in the NBA with the Los Angeles Lakers, Denver Nuggets, Dallas Mavericks, Golden State Warriors, Portland Trailblazers and San Antonio Spurs, the website said.