The suspect in a deadly military recruiting center shooting in Little Rock, Ark., conducted Google Map searches of several sites there and in other U.S. cities, a law enforcement official tells FOX News.
The FBI and the Department of Homeland Security sent out an "e-mail alert" Tuesday night to local and state law enforcement, according to the official. The source said they did not issue an "intelligence assessment" about the 23-year-old accused shooter, Abdulhakim Muhammad, as has been reported.
"Although the June 1 shooting was limited to Little Rock ... [we] notified specific cities, and out of an abundance of caution, issued the alert because additional subjects, targets or the potential for inspired copycats could not be ruled out," the official told FOX. "This remains an open and ongoing FBI investigation."
Also Wednesday, The Associated Press, also citing an unnamed official, said some of the sites searched and mapped out on Google were Jewish organizations, a child care center, a Baptist church, a post office and military recruiting centers in the southeastern U.S. and New York and Philadelphia.
After Monday's attack outside the Army-Navy Career Center in Little Rock, detectives scoured a computer linked to Muhammad, where they said they discovered the research into multiple sites in different states.
The news of more targets allegedly found on Muhammad's computer suggested that he may have been part of a larger attack plot and may not have been acting alone, a senior U.S. official told FOX earlier.
Muhammad, 23, a U.S. citizen and Muslim convert who previously was known as Carlos Bledsoe, pleaded not guilty to capital murder in the deadly suburban shopping complex shooting.
Authorities said he targeted soldiers "because of what they had done to Muslims in the past."
Private William Long, 23, was killed and Private Quinton I. Ezeagwula, 18, was wounded. Both completed basic training within the past two weeks and had never seen combat. Ezeagwula was in stable condition at a hospital.
The latest information seemed to contradict a local police official's denial earlier Tuesday that the shooting was part of a larger conspiracy, though details of possible accomplices and their involvement weren't immediately disclosed.
Muhammad is being held without bond.
Muhammad is accused of carrying out a targeted attack against U.S. forces because of "political and religious motives" and already had been under investigation by the FBI at the time of the shootings.
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.
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, Little Rock Police Chief Stuart Thomas said on Tuesday.
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.
FOX News' Mike Levine, Jennifer Griffin and The Associated Press contributed to this report.