NEW YORK (CBSNewYork) - The man charged with protecting New York City from terror attacks took a first-hand look at the crime scene atop one of New York's most iconic landmarks.
NYPD Deputy Commissioner John Miller visited the Brooklyn Bridge Friday, climbing to the top of the towers. Miller visited the flagpoles where vandals replaced American flags with whitewashed versions on Tuesday.
Miller spoke exclusively with CBS 2's Jessica Schneider about the seemingly death-defying climb and his investigation into the flag swapping incident.
"We learned what we went up there to learn, but we didn't find anything additional in terms of physical evidence," Miller said.
PHOTOS: Mysterious Brooklyn Bridge Flags
Investigators said they want to know how the likely daredevils made the climb, but in the middle of night, in pitch black conditions.
It remains unknown if they had any equipment or any special skills.
For days police have been pouring over surveillance video taken from cameras on the bridge.
At 3:10 a.m. Tuesday, police said video shows at least four or five people crossing the bridge on foot. Police still have not identified those persons of interest, Schneider reported.
At around 3:30 a.m., the video captured by Earthcam shows the lights illuminating the American flags go dark. All it took to shut down the lights were aluminum lasagna pans, secured over the flood lights with zip ties.
It wasn't until 5:30 a.m. that construction workers at the bridge noticed the whitewashed flags flying high above.
"The investigation is progressing. We have a lot to go through. We've received a number of leads. We are encouraging members of the public to provide more leads," Miller told Schneider.
The NYPD has also spent days interviewing construction workers about their political views or possible gripes with the government – anything to find out why and how the 20-foot by 11-foot homemade whitewashed flags started flying above one of the most recognized bridges in the world, Schneider reported.
Residents said Miller's expedition to the top of the bridge Friday was comforting.
"There's probably a hundred thousand tourists walking back and forth every day, hundreds of thousands of cars including one with me in it going back and forth," said Zachary Rubin. "I'd like it to be secure and I'd like people walking around the city knowing it's secure."
"It's just a little scary that people can scale a bridge and no one sees it, especially with the heightened security," said Catherine St Pierre.
When asked about the climb and the view from the top of the bridge, Miller said, "There's a principle that you don't ask your people to go anywhere you wouldn't go yourself, and I would be less than honest to say it was an interesting experience."
NYPD Deputy Commissioner Offers Insight Into Brooklyn Bridge Flag Incident
The NYPD is conducting an extensive investigation into the incident. Investigators are examining DNA evidence that was found at the scene as well as license plates of vehicles that were on the bridge at the time and cellphone transmissions from the bridge, Schneider reported.
The breach prompted a massive increase in security at the bridge.
Among other changes, the stepped-up security measures include new cameras, officers on foot patrol, and helicopter flyovers.
The breach has also prompted plans for security upgrades at other iconic sites around New York City.
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