Eric said his brother, who was found dead in a hotel room following Sunday night’s shooting, was retired, had no known interest in firearms.
In an interview with the Orlando Sentinel newspaper, the Florida resident said that he can’t understand what happened.
“He has no police record, he doesn’t even have parking tickets, probably,” the brother said in an interview outside his home.
“He was not an avid gun guy at all. The fact that he had those kind of weapons it…just where the hell did he get automatic weapons? He has no military background or anything like that,” Eric said.
He added that the entire family is “shocked, horrified, completely dumbfounded,” and they hadn’t noticed any troubling signs. Eric noted that the brothers, who live in different states, weren’t that close and talked on the phone occasionally.
“If there was anything I could have done I would have done it.”
During the interview, Eric read out the final messages that he received from Stephen.
WATCH: Suspect’s weapons, methods suggest planned attack
“How’s mom?” one of the last ones read.
Eric pleaded with reporters that they leave his 90-year-old mother alone, adding “she has nothing to say.”
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While the family was shocked to learn of Stephen Paddock’s actions, authorities have narrowed down some details on his life before the attack.
According to local police in Nevada, Paddock owned a single-family home in Sun City Mesquite. He lived with a 62-year-old woman, who was out of the country at the time of the shooting.
— With files from The Associated Press