A convert to Islam accused of having "political and religious motives" in a deadly Arkansas military center shooting pleaded not guilty to capital murder Tuesday and was ordered held without bond.

One soldier died and another was wounded in what police say was a targeted attack by Abdulhakim Mujahid Muhammad, 23, on U.S. forces.

Muhammad, an American citizen who is a convert to Islam and previously was known as Carlos Bledsoe, already had been under investigation by the FBI at the time of the shootings.

Muhammad was charged in Monday's death of Pvt. William Long, 23, outside the Army-Navy Career Center, which handles recruiting, in Little Rock.

A prosecutor said Muhammad admitted shooting Long and another soldier "because of what they had done to Muslims in the past."

Long and Pvt. Quinton Ezeagwula, 18, had recently completed basic training and had never seen combat. Ezeagwula was in stable condition at a hospital.

An FBI joint terrorism task force based in the southern U.S. reportedly had been tracking Muhammad after he traveled to Yemen and was arrested and jailed there for using a Somali passport, an official told The Associated Press. The probe had been in its early stages and based on Muhammad's trip to Yemen, ABC News reported.

While there, Muhammad, who was born and raised in Tennessee, studied jihad with an Islamic scholar, according to Jihadwatch.org. He moved to Little Rock in April.

After the shooting, investigators searched his apartment and found additional weapons, the official, who spoke on condition of anonymity, told the AP.

An FBI spokesman in Little Rock did not immediately return a call for comment.

At Tuesday's court hearing, Deputy Prosecutor Scott Duncan said Muhammad told investigators that "he would have killed more soldiers had they been in the parking lot."

Long and Ezeagwula were targeted as they stood outside the recruiting center smoking cigarettes.

Muhammad, wearing a dark blue jail uniform with brown plastic sandals, sat with his hands in his lap before Little Rock District Judge Alice Lightle. He did not say anything during the brief hearing.

Investigators described the killing as one motivated by politics and religion: A Muslim convert upset with the U.S. military drove to a recruiting center and opened fire.

Muhammad was not part of any organized terrorist group, nor was his attack part of a larger conspiracy, according to Little Rock Police Chief Stuart Thomas.

Interviews with police show that the suspect "probably had political and religious motives for the attack," Thomas said. "We believe that it's associated with his disagreement over the military operations."

Muhammad told authorities that he approached the recruiting center in Little Rock by car on Monday and started shooting at two soldiers in uniform, according to a police report.

"He saw them standing there and drove up and shot them," Lt. Terry Hastings told the AP. "That's what he said."

The two victims had completed basic training within the past two weeks and were not regular recruiters, said Lt. Col. Thomas F. Artis of the Oklahoma City Recruiting Battalion, which oversees the Little Rock office.

Witnesses told police that a man inside a black vehicle pulled up outside the recruiting center and opened fire about 10:30 a.m. Long fell onto the sidewalk outside the center, while Ezeagwula was able to crawl toward its door.

Muhammad was arrested along an interstate highway moments after the shootings, authorities said.

Police said an assault rifle and other weapons were found in Muhammad's car when he was arrested.

The accused shooter's father, Melvin Bledsoe, hung up on a reporter who called about his son's arrest Monday night.

The Associated Press contributed to this report.