7:45 p.m. CDT
A federal law enforcement official says authorities had an open investigation into accused gunman Elton Simpson at the time of a shooting at a Texas cartoon contest, according to AP reporter Eric Tucker in Washington.
The official wasn't authorized to discuss the ongoing investigation by name and spoke on condition of anonymity. The official also said investigators will be studying the contacts the men had prior to the shooting, both with associates in the U.S. and abroad, to determine any additional terror-related ties. The Islamic State group has claimed responsibility for Sunday's assault.
The event in Garland, a Dallas suburb, featured a deliberatively provocative contest for images of the Prophet Muhammad. Simpson and another man opened fire outside the event. Both men were killed by an officer. A security guard was injured.
2:30 p.m. CDT
The White House says "it's too early to say" whether U.S. officials have been able to corroborate claims that the Islamic State group is responsible for a shooting outside a Prophet Muhammad cartoon contest in Texas.
White House spokesman Josh Earnest said Tuesday that the IS group and others were trying to capitalize on social media to radicalize people in the U.S.
Earnest says U.S. officials are aggressively working to counter those efforts, and "it's something that we continue to be vigilant about."
When asked if the Islamic State group has now come to the U.S., Earnest said: "We would certainly want to make sure that we know a whole lot more about the facts" before drawing such a conclusion.
Two gunmen opened fire Sunday night outside the event center hosting the event in Garland, a Dallas suburb. Both men were killed by an officer. A security guard was injured.
11 a.m. CDT
About 50 Islamists held a special service Tuesday in Pakistan for two men who were killed in Texas after they opened fire at a cartoon contest featuring images of the Muslim Prophet Muhammad.
The cleric Mohammad Chishti led the service for Elton Simpson and Nadir Soofi at a public park in northwest Pakistan.
Chishti told journalists that the two men were martyrs and that he organized the service to pay tribute to them.