LAS VEGAS (CBSLA/AP) — Las Vegas police on Wednesday released some officer body-camera video from the deadliest mass shooting in modern U.S. history, footage which comes one day after authorities revealed the first officer on the scene didn’t activate his body-worn camera.

The videos were expected to show what two officers found entering a 32nd-floor hotel room where Stephen Paddock unleashed gunfire on a concert last October. Police and the FBI have said he killed 58 people and injured hundreds more before killing himself as authorities closed in.

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Police say the clips come from cameras worn by two different canine officers, Sgt. Joshua Bitsko and David Newton.

The footage will not show what the first officer through the door, Levi Hancock, saw because he didn’t activate his body-worn camera. That disclosure by police lawyers late Tuesday raises questions about whether officers followed department policy.

It wasn’t immediately clear why Hancock – a SWAT officer who had been on the force since Jan. 2001 – did not activate his body camera, the Las Vegas Review Journal reported.

The newly released videos represent a sample of hundreds of hours of body-camera recordings that don’t answer why Paddock opened fire, Clark County Sheriff Joe Lombardo told reporters Tuesday.

Police and the FBI have said they believe Paddock, a 64-year-old former accountant and high-stakes video poker player, acted alone.

The police investigation was not finished, said Lombardo, who oversees the department and called the preparation and release of documents sought by the media a “monumental task” that would divert resources from police work.

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“What is seen on those videos in no way changes the facts that we were able to clarify for you shortly after the crime,” he said.

Lombardo referred to a preliminary police report released Jan. 19 that said Paddock meticulously planned the attack, researched police SWAT tactics, rented hotel rooms overlooking outdoor concerts and investigated potential targets in at least four U.S. cities.

An undated image from police of Stephen Paddock’s Mandalay Bay hotel room (Photo via LVMPD)

The sheriff’s top spokeswoman, Carla Alston, said Wednesday that no one in the agency would comment about whether the first officer through the door followed proper procedure by not activating his camera or whether he had been disciplined for violating policies.

The Police Department requires officers to activate body cameras during calls that lead to interaction with residents and searches.

The Associated Press and other media outlets sued to obtain videos, 911 recordings, evidence logs and interview reports. Lombardo said the department would release more records in batches in coming weeks.

“We believe the release of the graphic footage will further traumatize a wounded community. For that, we apologize,” he said.

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(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)