Nearly a half-hour after Nikolas Cruz dropped his rifle and fled Marjory Stoneman Douglas High School, police thought they were seeing him live on security cameras, still in the building. They were actually seeing images tape-delayed.

The Broward School District’s security cameras did not provide real-time video for police, complicating their efforts to track and pin down the shooter, the South Florida Sun Sentinel has learned.

“He went from the third floor to the second floor … They’re monitoring him on camera,” an officer said on radio transmissions recorded by Broadcastify, an audio streaming website, at 2:54 p.m. In fact, Cruz was already long gone — he had escaped the school’s freshman building 26 minutes earlier, a timeline released by the Broward Sheriff’s Office shows.

The video images were “delayed 20 minutes and nobody told us that,” said Coral Springs Police Chief Tony Pustizzi.

Pustizzi said the video delay made a chaotic situation more confusing, but he does not believe it delayed efforts to rescue injured students. “We got in so fast, we’re pulling them out. It made it harder to identify where the guy was.”

According to the sheriff’s office, Cruz began shooting into classrooms at about 2:21 p.m. and left the building seven minutes later. Authorities eventuallycaptured him more than an hour after he left the school.

Fourteen students and three educators died in the Valentine’s Day killings. Cruz, a troubled former student of Stoneman Douglas, confessed and could face the death penalty.

Police radio transmissions reviewed by the Sun Sentinel reveal more details about the confusion at the scene as officers tried to determine what was happening and how best to respond to the worst school shooting since the Sandy Hook Elementary School massacre in 2012.

They show:

— At the same time the shooter escaped, police were saying they were entering a building, though it’s unclear from radio transmissions whether it was the right building or a neighboring one.

— Police initially could not get to the security cameras and couldn’t immediately find someone to help them.

— Police communication was hampered by outmoded radios that left some transmissions inaudible.

The school is in Parkland, which is protected by the sheriff’s office. Also, an armed sheriff’s deputy — called a school resource officer — is assigned to the school.

At one point, police were looking for that officer, Scot Peterson, because he “would be the one to have access to where the cameras are,” according to the police radio broadcast.

Peterson was on the 45-acre campus during the attack but not in the targeted building, Schools Superintendent Robert Runcie previously told the Sun Sentinel.

“We need somebody with the camera systems ASAP,” an officer stated at 2:43 p.m., about 15 minutes after the shooting stopped, according to the sheriff’s timeline. “Where’s the principal? Who’s with the principal? And we need to start making a plan here.”

Broward Sheriff Scott Israel said at a press conference Wednesday that he did not know anything about delays in school security video but said he would look into it.

His agency, earlier in the day, notified media that the sheriff’s timeline — released on Feb.15, the day after the shooting — is approximate and may change as an official review is conducted.

Asked whether police went into the school immediately, the sheriff said “that’s exactly what we’re examining.”

Once inside the freshman building, police struggled to determine where the shooter was. They watched Cruz on camera, seeing him drop his bag near the stairway as sirens blared in the background. An armored vehicle sat at the ready.

But by then Cruz was gone, sitting at a McDonald’s about a mile away.

“It’s about a 20-minute delay they’re following him on video, on the camera,” an officer said over the radios. “They have him exiting the building, running south.”

Pustizzi described the chaos over the shooter’s whereabouts. “Somebody would say: ‘He’s on the second floor,’ and we had guys on the second floor saying: ‘We’re on the second floor, we don’t see him.’ That’s when we figured out there’s a tape delay.”

“Once we found that out we were able to adjust.”

The cameras are not controlled by the Broward Sheriff Office but by the School Board, Pustizzi said.

A school district spokesperson did not respond to questions posed by the Sun Sentinel.

Pete Blair, a criminal justice professor and executive director of the active shooter response program at Texas State University, said such a long camera delay is unusual.

“I’ve never heard of that problem before,” he said of the more than 20-minute delay. “That’s going to slow you down because you think that’s good information, but it’s not good information.”

As the officers on the scene dealt with the problematic cameras, they also struggled with “some sort of feedback” on the radio system.

A Sun Sentinel investigation last year found that a crush of law enforcement officers responding to the Jan. 6, 2017 shooting at Fort Lauderdale airport overwhelmed the county’s antiquated radio system, disrupting communications. Some police could hear but not talk as they were trying to determine if there was a second shooter.

Broward County Commissioners in May approved $59.5 million to replace the more than 25-year-old radio system, but it won’t be ready to use until the end of this year, officials said at the time.

During the Stoneman Douglas shooting, a dispatcher warned all units at 2:56 p.m. that the radios were malfunctioning. “You can hear me, but I cannot hear you, so standby.”