Christmas, who was charged with two counts of firearms violations, was arraigned about 4:30 a.m. and his bail was set at $10,000, officials said. He was released shortly after that.
The case is being investigated by Northwest Detectives.
Ownership of the gun was still being determined yesterday, but Christmas' agent, Andre Buck, said it does not belong to Christmas.
Speights, who was with the Sixers for last night's preseason game against the New Jersey Nets in Queens, N.Y., was not made available to comment on the matter by the Sixers.
"It's a serious and unfortunate situation," Buck said. "We hope to get it resolved quickly. It's a situation where a really good kid made a mistake. . . . What's most upsetting is driving without a license in this case could lead to a bigger problem. It has escalated because of alleged possession of a firearm."
Christmas is scheduled for a preliminary hearing within three to five days.
After yesterday's Sixers practice, coach Eddie Jordan addressed Speights' involvement.
"We spoke in the huddle about the situation, and I don't want it to be a distraction to him," Jordan said.
"He's going to be distracted just because of human nature. We want him to feel free. Usually when you come to the basketball court, you free yourself from all other distractions."
"We're just going to wait until the NBA and our front office come to some sort of resolution and action after all the facts have been sorted out," Jordan said.
Although Christmas left Temple as the three-time Atlantic Ten scoring leader, he was not selected in the June NBA draft. He played for the Sixers/Nets squad that competed in the Orlando Pro Summer League, and he later joined the Sixers for preseason camp as a free agent.
Contact staff writer Kevin Tatum at (215) 854-2583 or ktatum@phillynews.com.
Inquirer staff writers Troy Graham and Kate Fagan contributed to this article.