EDITOR'S NOTE:This story contains graphic descriptions of violence. During evening rush hour in New York City on Monday, a man calmly walked into a Park Avenue office building lobby and killed a police officer, then opened fire on other innocent strangers. Within a minute, the gunman had disappeared into a labyrinth of elevator banks and hallways, armed and loose somewhere in the 44-story building. The day's violence would become the deadliest mass shooting in New York City since 2000. The gunman shot and killed four people and wounded another, before killing himself, police said. From the moment the first panicked 911 calls were received, the New York Police Department unleashed a torrent of cops, specially trained units, heavy weapons, sophisticated technology and a swift information exchange among its 32,000 police officers and law enforcement partners across the country. As calls flooded in, the NYPD's electronic log system captured the horror happening in real time inside the Park Avenue skyscraper. The shorthand notes, obtained by CNN, show the desperation of frightened callers as operators attempted to piece together what was happening. "INVESTIGATE/POSSIBLE CRIME: SHOTS FIRED/INSIDE\ACTIVE_SHOOTER," read one note. "ACTIVE SHOOTER IN THE BUILDING AND LOCKED SELF IN ROOM," the log notes a female caller reported. Additional calls are logged: "7-8 SHOTS HEARD," "LOCATION IS NFL HEADQUARTERS," "SHOOTER IN BUILDING." Another female caller reported her husband telling her he's in a locked room, according to the log. From precinct officers to specialized commands, swarms of law enforcement teams raced to the scene. The NYPD's Emergency Service Unit, which operates as a SWAT team, entered the building and began a systematic search for the gunman, who was somewhere inside. At the same time, officers from the Strategic Response Command, providing an additional long-weapons team, set up a perimeter and established a safe corridor known as a "warm zone" to get medical personnel in and wounded victims out while the search for the gunman continued, law enforcement officials said. While those teams secured the area outside, detectives made their way into the skyscraper and examined surveillance video in the building's control center. They took a screengrab of the gunman, and using technology developed by NYPD Commissioner Jessica Tisch, blasted the image to NYPD officers' department-issued phones. Within minutes, every officer searching the building or holding the outside perimeter had a picture of a man taking large strides and carrying an assault rifle, the officials said. The gunman was identified after responding teams found his body on the building's 33rdfloor: 27-year-old Shane Devon Tamura of Las Vegas, Nevada. New details from law enforcement sources shed light on Tamura's travel to New York City, the gunman's movements inside the building and the police investigation. Here's what we've learned about the shooting at 345 Park Avenue: Officers found Tamura's black Series 3 BMW double-parked in front of the Park Avenue building, and then used his name, vehicle registration and a disjointed suicide note found in his back pocket to pull together a timeline of Tamura's path to the carnage. On Saturday, July 26, two days before the shooting, a license plate reader in Loma, Colorado, recorded Tamura's car with Nevada license plates passing through at 1:06 p.m., according to a law enforcement official. On Sunday, Tamura did not show up for his surveillance job as part of the security team at the Horseshoe Casino in Las Vegas. He was miles away. Tamura's black BMW was spotted driving eastbound on Interstate 80 by a license plate reader (LPR) owned by the Nebraska State Patrol. Later, an LPR operated by the Scott County Sheriff's Office recorded the car on I-80 near Wolcott, Indiana. At 4:24 p.m. Monday, a camera attached to the New Jersey State Police's real-time crime center took a picture of his BMW, this time along I-80 in Columbia, New Jersey, nearly two hours before the rampage would begin. Two senior law enforcement officials who reviewed video from the Midtown Manhattan office building provided the following account of the gunman's movements on Monday: At 6:26 p.m., Tamura double-parked outside 345 Park Avenue. He got out of the car carrying the M4 semi-automatic rifle, crossed the sidewalk and then the broad plaza leading to the office building's entrance. One minute later, Tamura entered the building. Inside, Tamura turned to his right to face uniformed NYPD officerDidarul Islamand shot him, killing the 36-year-old father of two who was expecting his third child. As Islam fell, Craig Clementi, who works in the NFL's finance department, was also shot. Clementi called his coworkers to warn them that a gunman was in the lobby firing shots, and then called 911, according to one of the senior officials. Wesley LePatner, a 43-year-old Blackstone executive, was shot as she moved toward a pillar in the lobby, police said. LePatner died from her wounds. Tamura then shot Aland Etienne, a 46-year-old security guard. Wounded, Etienne crawled toward the console behind the security desk and collapsed. Tamura went to an elevator bank on the opposite side of the lobby to the elevators that go up to the NFL offices. Officials have said investigators believe Tamura was headed for the NFL offices at the time of the shooting, buttook the wrong elevator. He ignored a woman exiting an elevator car, entered it and then pressed 33, the lowest available on its panel, according to one of the senior law enforcement officials. Once on the 33rd floor, Tamura faced glass walls with locked doors on either end of the hallway. These were the offices of Rudin Management, the company that runs the building. Tamura tried opening the doors, then opened fire on the glass and kicked through it to enter the floor, officials said. By then, it was likely he realized he wasn't at the NFL offices, according to the officials. Tamura saw an office cleaner,Sebije Nelovic,and opened fire but missed her, she said in a statement released by her union. Nelovic said she ran down the hallway and locked herself in a closet. She heard screams and more gunfire, she said, describing the gunman at one point shooting the door she was hiding behind. As shots rang out, frantic employees called 911 and barricaded themselves in offices and conference rooms. Their desperate calls reported how many shots they had heard, where they were hiding and where they believed the gunman was moving, according to a radio call log reviewed by CNN. Over the years, Rudin Management conducted active shooter drills and training for its employees. Their offices on the 33rd floor have bathrooms designed as safe rooms, in the event of an incident just like the one that unfolded Monday, the officials said. The rooms are outfitted with bullet-proof doors that lock with bolts from the inside, and their walls are lined with Kevlar. Each bathroom is equipped with a video feed showing the hallway outside and a dedicated telephone line. Julia Hyman, a 27-year-old Rudin Management employee who was working late, was in one of those very bathrooms designed as a safe room. It is not clear whether she had heard the shots or understood what was unfolding outside. She stepped outside the bathroom, and walked three or four steps, apparently unaware that the gunman was behind her. He fired, striking her in the back. Wounded, Hyman stumbled to her desk and died from her wounds, according to one of the officials who reviewed the video. By this time, it appeared Tamura realized there were no more accessible targets in the office, and, with police swarming the building, it was not likely he was going to find his way to the NFL, the official said. A few seconds after shooting Hyman, video is said to show Tamura stood next to a desk, held out his arms to aim the rifle at his own chest and used his thumb to pull the trigger, firing a single round, the official said. His body dropped to the floor, his rifle falling next to him. Tamura had fired most of two 30-round magazines of .223 ammunition in a matter of minutes, the official said. Throughout the night and into the morning, police collected evidence from where the victims lay and from the areas where shots were fired. In the building lobby, 23 shell casings and more than a dozen ricocheted bullet fragments were recovered, according to an NYPD official. In the 33rd floor offices of Rudin Management, investigators from the NYPD's Crime Scene Unit found another 24 shell casings from Tamura's M4 rifle, as well as 15 bullet fragments, the NYPD official said. Bureau of Alcohol, Tobacco, Firearms and Explosives agents on the scene received the rifle's serial number, and within minutes detectives learned the rifle had been purchased on August 29, 2024, by a Las Vegas man identified as "Rick," a coworker of Tamura's at the Horseshoe Casino, according to documents reviewed by CNN. "Rick" has not responded to CNN's requests for comment. The NYPD Intelligence Bureau's SENTRY unit, which maintains a national network of law-enforcement contacts, then reached out to Las Vegas Sheriff Kevin McMahill, who sent detectives to interview "Rick." "Rick" had also sold Tamura the black BMW he drove across the country, according to Nevada DMV records. Other Las Vegas sheriff's deputies were dispatched to Tamura's apartment to seal it while awaiting a search warrant. Another team went to interview Tamura's parents, who lived nearby. The Las Vegas Metro Police Crime Stoppers hotline received a call at 8:25 p.m. the night of the shooting. A licensed gun dealer had seen the picture of Tamura and remembered his face. In June, he had sold him a modified trigger for an M4 rifle. Tamura had also told the dealer that he planned to buy 500 rounds of .223 ammunition for the assault rifle, a law enforcement official told CNN. Back in New York, Tamura's BMW was cleared by the bomb squad. Detectives recovered 827 rounds for a stainless steel .357 magnum Colt Python revolver. According to the same official, the gun was fully loaded with another six rounds in the cylinder. For more CNN news and newsletters create an account atCNN.com
