NEW YORK (CBSNewYork) — The NYPD is stepping up security in high profile locations throughout the city following a concert shooting in Las Vegas that left at least 59 people dead in what has become the deadliest mass shooting in modern U.S. history.

Additional counterterror units have been deployed in Times Square and other strategic locations as a precaution.

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“It’s one of the perils of living in an open, free democratic society. Here in New York City we’re monitoring the investigation and have deployed personnel to strategic locations at an abundance of caution,” NYPD Commissioner James O’Neill said Monday morning during a training conference for domestic violence officers at police headquarters.

The department says it will take every necessary measure Tuesday night, when more than 50,000 people are expected at Yankee Stadium for the American League Wild Card game.

O’Neill said the department knows of no direct threat to New York City.

“But we’ll certainly be maintaining our vigilance as we move further into the fall, the winter and the holiday season,” he said. “As for today, we’re keeping everyone affected by the events in Las Vegas in our thoughts. I ask that you do that as well.”

The NYPD terror response has been honed over many years and countless events, and often includes special units positioned at vantage points.

“You will have marksmen, spotters at the very tops of the stadium and at strategic points, there will be acoustic detectors in the event that there’s a firearm discharge that will help pinpoint the shooter,” security expert Anthony Roman told CBS2’s Tony Aiello.

Tens of thousands of people visit Times Square daily, making it one of the busiest tourist locations in the world.

“When I saw on TV what happened in Vegas, I thought about Times Square right away,” ticket vendor Bernardo Silva told CBS2’s Hazel Sanchez. “That can happen anytime, that’s why we have to worry about it.”

More than a million people pack Times Square every New Year’s Eve, surrounded by countless high rise and hotel rooms, which have perfect views of the crowds below.

“It just makes you think you can’t even go into concerts outside because you’re exposed to danger,” said Shonna Famularo of Asbury Park.

“I think they should check everybody’s bag before they get into their rooms, about their weapons,” Silva said, “because Times Square is where everybody comes.”

Counterterrorism experts say that idea is not farfetched and is currently a practice overseas.

“It’s interesting because when you travel in Africa, Europe, India, oftentimes, in the wake of the Mumbai attacks, you’ll recall, in the Taj hotel, they do now screen visitors when they come into hotels,” said Frances Townsend, CBS News’ National Security Analyst. “They screen your luggage, they screen you.”

Some travelers feel hotel baggage screening is extreme.

“Do I have to have everybody look at that over and over again? Then we become prisoners in our free land,” Steve Bolhous said.

Security expert Manny Gomez says hotel baggage screening in New York would be beneficial, but currently is unlikely.

Gomez says the NYPD and Homeland Security have safety measures in place, both seen and unseen, and event organizers need to consider location.

“At the very least, these public events, they’re going to have to be revisited,” Gomez said. “Maybe placed in other places where they’re not easy targets from hotel rooms like this one is. This was obviously planned, this did not happen at random.”

On Twitter earlier Monday, the NYPD Counterterrorism Bureau tweeted: “We are monitoring the developments with the events that occurred in the @CityOfLasVegas, as we keep the victims in our thoughts & prayers.”

In another tweet, the NYPD said “we stand united” with the Las Vegas Metro Police Department.

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“Our prayers are with the families of those killed & injured,” the NYPD said.

Speaking at an event Monday, Mayor Bill de Blasio said “once again, we have confronted something in our country that is unspeakable.”

“It’s a very painful reality and our hearts go out to all the families who have lost loved ones,” he said.

Gov. Andrew Cuomo ordered all flags on government buildings to be flown at half-staff.

“Once again the nation mourns in the wake of yet another senseless and horrific mass shooting. New York stands with Las Vegas in the aftermath of this heinous and vile act of gun violence and my heart aches for its victims and their loved ones on this darkest of days,” he said in a statement.

Meanwhile, there was some anxiety Monday evening as fans filed into the Katy Perry concert at Madison Square Garden. One 16-year-old girl named Gabi said it took a little convincing to get her parents to let her come.

“My entire community was so concerned too. I just have to look out for myself,” she told 1010 WINS’ Al Jones. “But I feel safe here. I don’t think anything’s going to happen. I hope nothing happens.”

Another girl, Victoria, admitted to some apprehension.

“But I feel like we’re safe here, because New York has a lot of precautions, and I already know at MSG they check bags, and you know, so I know we’ll be safe,” he said.

But David Jozniak said what we cannot do is let the fear of terrorism change what we do.

“We can’t let the terrorists win, like, we have to go out living our lives and do what we do,” he said. “If not, they’ve won.”

On Long Island, state park police are looking into whether any additional safety measures should be taken at the Jones Beach Theater, WCBS 880’s Sophia Hall reported.

Earlier this year, barriers were added in front of the theater, along with screenings before getting inside and bomb-sniffing dogs.

“Everyone that goes into the venue is screened by Live Nation security. No items can be brought into the stadium,” spokesman George Gorman told Hall. “There are no high buildings or anything like that, that is in close proximity to the theater.”

He added that concert season has wrapped up. It will begin again in May.

“This incident – the New York State Park Police will again reevaluate to look at the security measures to determine if there are any improvements that we need to put in place,” he said.

Roman says Las Vegas is going to have to ask some tough questions as it analyzes how the mass murder unfolded. Primarily, were there any red flags as the gunman brought 19 weapons and thousands of rounds of ammo into his room at the hotel.

Authorities say  64-year-old Stephen Paddock, opened fire from the 32nd floor of the Mandalay Bay Hotel and Casino across the street from the Route 91 Harvest Music Festival in Las Vegas Sunday night.

Police said he was found dead in a hotel room.

“During the time he was being brought to his room, that suspicions may have been raised by the disproportionate weight, the heaviness of the luggage and the material that he was carrying,” Roman said.

In New York City, police work closely with hotels to gather information on suspicious activity. Workers are encouraged to say something when they see something unusual.

Some say that hotels should check every guest’s bag before they get to their rooms, but Roman says the industry has avoided boosting security to that extreme.

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“It’s also a hospitality industry, and it’s not considered particularly hospitable to put guests through the type of screening they undergo at airports and other secure facilities,” he said.