Dallas - The mother of one of the suspected gunmen involved in a planned attack on a Prophet Muhammad cartoon contest in Texas, US, has said she had no idea her son would turn to violence.The Dallas Morning News reported that Sharon Soofi, the mother of suspected gunman Nadir Soofi, said her son was raised "in a normal American fashion" and was "very politically involved with the Middle East”.She said she doesn't know if "something snapped"."He put his son above everything, I thought,” she told the newspaper. “The hard thing is to comprehend is why he would do this and leave an 8-year-old son behind."Authorities shot and killed Nadir Soofi and another man outside the Curtis Culwell Centre in Garland, Texas, on Sunday night. Police said they opened fire on an unarmed security guard outside a Prophet Muhammad cartoon contest.‘Saved lives’Texas police, meanwhile, said the officer who fatally shot the two gunmen likely saved lives.Garland Police Officer Joe Harn didn't release the name of the officer, but said: "His reaction, and his shooting with a pistol, he did a good job."Harn says officers were able to stop the two gunmen before they were able to get inside the suburban Dallas venue hosting the event and shoot anyone else.A security guard was shot and wounded during the incident on Sunday night.