(Reuters) - Police and FBI on Monday searched the Arizona apartment of one of two gunmen shot dead on Sunday after they allegedly opened fire outside a Texas exhibit of caricatures of the Prophet Mohammad.
Citing a senior Federal Bureau of Investigation official, ABC News identified one of the gunmen as Elton Simpson, an Arizona man who was the target of a terror investigation. FBI agents and a bomb squad were searching Simpson's Phoenix home, ABC said.
Phoenix's KPHO TV reported an unidentified second man lived in the same complex as Simpson, the Autumn Ridge Apartments. It was not immediately clear whether the two men lived in the same apartment.
Phoenix police and the FBI did not immediately comment. A police officer outside the apartment building could not confirm details of the search inside.
The shooting in a Dallas suburb was an echo of past attacks or threats in other Western countries against art depicting the Prophet Mohammad. In January, gunmen killed 12 people in the Paris offices of French satirical magazine Charlie Hebdo in what it said was revenge for its cartoons.
The event in Garland, Texas, organized by American Freedom Defense Initiative (AFDI), was called "Muhammad Art Exhibit and Contest" and offered a $10,000 prize for the best artwork or cartoon depicting the Prophet.
The event featured speakers including Geert Wilders, a polarizing Dutch politician and anti-Islamic campaigner who is on an al Qaeda hit list.
The AFDI, described by the Southern Poverty Law Center as a hate group, has among other activities sponsored anti-Islamic advertising campaigns in transit systems across the country.
ABC News said officials believed Simpson sent out tweets ahead of the attack, with the last one using the hashtag #texasattack. It said, "My bro and myself have given bay'ah to Amirul Mu'mineen. May Allah accept us as mujahideen. Make dua."
"Bay'ah" means "oath of allegiance" in Arabic, and "Amirul Mu'mineen" is "commander of the faithful," a title of caliphs and other Muslim rulers. "Dua" means "supplication." The tweet was pulled from Twitter after the attack.
Phoenix TV station KTVK reported that neighbors at Autumn Ridge said a man and his brother lived in the apartment that was being searched.
"They were really into the Muslim thing," neighbor Craig Gibbons told the TV station, without providing any identification of the suspects. "They would talk to you for a couple hours about (the religion). But they were nice."
A fighter for Islamic State, a militant group which has taken over large parts of Iraq and Syria, said in a tweet that "2 of our brothers just opened fire at the Prophet Muhammad (s.a.w.) art exhibition in Texas," according to the SITE Intelligence Group, a U.S.-based monitoring group.
Depictions of the Prophet Mohammad are viewed as offensive in Islam, and Western art that portrays the Prophet has angered Muslims and provoked threats and attacks from radicals.
SECURITY GUARD HURT
President Barack Obama was briefed on Sunday night about the shooting, a White House official said, speaking on background.
Pamela Geller, president of the AFDI, defended the exhibit on Monday.
"In a pluralistic society you have offensive speech, you have ideas, you have an exchange of ideas, you don't shut down a discussion because 'I'm offended.'" she said in an interview on CNN.
The attack on Sunday took place at about 7 p.m. local time in a parking lot of the Curtis Culwell Center, an indoor arena in Garland, northeast of Dallas.
At the scene in Garland on Monday, a police helicopter flew overhead and the area was cordoned off by police. Three crime scene investigators were in the street near the shooting.
Very early on Monday, police alerted reporters that a strong electronic pulse would be activated near the scene, presumably as part of the bomb squad's work, and a loud boom was heard moments later, though police did not comment further.
In Sunday's incident, the two suspects drove up to the building as the event was ending, and opened fire with automatic rifles at an unarmed security officer, striking him in the leg.
Garland police officers who were assisting with security returned fire, killing both suspects, a police spokesman said.
The security officer was treated at a local hospital and later released, Harn said. No one else was injured.
Most of the 200 people attending the event were still inside the arena when the violence unfolded and unaware of what had happened until later.