Brother of Las Vegas Mass Shooter Detained in Child Porn Investigation

Bruce Paddock, the estranged brother of Las Vegas mass shooter Stephen Paddock, has been detained by Los Angeles authorities on accusations of possessing child pornography, PEOPLE confirms.

Paddock was taken into custody on Wednesday, as part of a joint investigation involving the Los Angeles Police Department and the Federal Bureau of Investigation, an FBI official tells PEOPLE.

Bruce Paddock is not considered a suspect in the Las Vegas massacre, according to police. After the shooting, another brother, Eric Paddock, spoke out about his shock at the shooting.

Detectives had been investigating Bruce Paddock for months before the Oct. 1 mass shooting in Las Vegas, in which 58 people were killed and hundreds were wounded, the official tells PEOPLE.

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The 58-year-old was detained while at a Los Angeles assisted-living facility, where he was awaiting surgery for spinal stenosis.

Bruce Paddock has not been booked yet, but the official tells PEOPLE charges are expected to be filed sometime today.

It was not immediately clear Wednesday if he has retained an attorney.

Bruce’s brother, Stephen Paddock, committed suicide after firing upon the Route 91 Harvest Festival in Las Vegas earlier this month. Country artist Jason Aldean was performing on stage when he began shooting.

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A motive for the mass killing has not been released by authorities investigating the murders.

Bruce and Stephen Paddock’s father, Benjamin Paddock, was a notorious bank robber who once occupied a slot on the FBI’s most wanted list.