Las Vegas gunman set up cameras at hotel

LAS VEGAS -- Police said Tuesday that Las Vegas gunman Stephen Paddock set up cameras inside his hotel suite and in the hallway.

Police are not aware whether the devices were transmitting -- the FBI is investigating their use -- but the Clark County sheriff said he thinks the shooter might have used them to watch for people approaching his room at the Mandalay Bay Resort and Casino.

No one knows why Paddock morphed from a retired accountant to the deadliest mass murderer in modern U.S. history. His relentless gunfire -- police say he fired for nine minutes after the first 911 call -- on country music fans at an outdoor concert left 59 people dead.

Another 500 people are still trying to recover from injuries -- everything from gunshot wounds to stampede injuries suffered when 22,000 people tried to flee the gunman's aim.

So far, police believe Paddock acted alone -- which could make the motive harder to determine.

Five handguns, two shotguns and a "plethora" of ammunition were found in Paddock's Reno, Nevada, property, Sheriff Joseph Lombardo said.

Authorities previously found 42 guns in Paddock's Las Vegas hotel room and at his Mesquite, Nevada, home.