NASHVILLE, Tenn. -- Nolan Richardson III resigned as men's basketball coach at Tennessee State University on Wednesday night, two weeks after he was indefinitely suspended for bringing a gun into the school's arena.

Richardson, 38, got into an argument with assistant coach Hosea Lewis on Christmas night concerning the time of practice after only four players showed up. Richardson admitted to campus police that he then went to his car and brought a handgun into the Gentry Center, the school's gym.

Assistant coach Christopher Graves said in a written statement to police that Richardson asked where Lewis was because he "had something for him."

Richardson, who told police the gun wasn't loaded, was suspended Dec. 26.

School officials said they will not pursue charges against Richardson for bringing the gun on campus.

"When a person engages in the type situation Nolan Richardson III engaged in -- no one can visualize that," Tennessee State president James A. Hefner said. "What he did is something that was beyond belief in terms of anyone in higher education doing something like that.

"It's abominable. It doesn't make sense." he said. "We don't tolerate it. That's why he was suspended, and that's why I have accepted his resignation."

Richardson was not available for comment.

Davidson County District Attorney General Torry Johnson said it is a felony to bring a gun onto school property in Tennessee. But he said his office has no plans to prosecute Richardson unless the university or Lewis asks him to pursue it. Campus police never forwarded the complaint, taken the day after the incident, to Nashville police.

"I'm pleased that I can say the situation has ended," Tennessee State athletics director Teresa Phillips said. "I'm really ready to move forward and look to bring some positive, new leadership for Tennessee State men's basketball."

Richardson was 23-41 since being given his first head coaching job in April 2000. He had been an assistant under his father at Arkansas for 10 seasons. The Tigers (2-9) have lost four straight under Lewis, who was named interim head coach.