Heavier police presence may be needed at large events after Chiefs shooting, experts say

Despite hundreds of police officers being on the scene of the Chiefs' Super Bowl celebration in Kansas City, Missouri, a mass shooting erupted, raising the question of how the tragedy could change security preparations at mass gatherings around the country.

One person was shot dead and 22 others were injured in what appears to have stemmed from a dispute, police said Thursday. At least half of those injured were under the age of 16, authorities said.  Three suspects have been detained, including two minors, and several firearms were recovered, police said.

There were 600 Kansas City Police Department officers and an additional 250 officers from outside agencies at the parade.

Robert Boyce, a former New York Police Department chief of detectives and ABC News contributor, said more officers were likely needed for an event that brought an estimated crowd of about 1 million people.

"The [New York] Yankees [World Series] parade that we've run many times, very similar to this, and also New Year's Eve, [are] two really difficult things to manage, there's no question. And it takes a lot of resources and I'm not sure 800 officers was enough," Boyce told ABC News in an interview.

"It's a two-mile strip, lots of stuff going on and you have a city that is challenged crime-wise," Boyce said. "They have a very high crime rate in the city, and has to be considered when you have these things."

Boyce said there would be a security presence of around 2,000 officers on the ground at comparable events in Manhattan.

"You really want to bring as many people as you can," Boyce said. "But we have a large department, we can do that."

"They'll have to take a look at that, [the police chief will] critique that, as she should," he added.

Boyce said it is likely the public will see an increased security presence at events with large crowds as law enforcement implements changes in response to mass shootings.

"When you have these events, you try to control them as best you can and you have access points to these events. We have what we call French barriers -- those are the metal ones -- and you try to control the crowd as best you can," Boyce said.

"They had a million people there, so you want people to arrive early. I think you had an 11 o'clock start for the event. So you want to get people there as early as 9 o'clock so you have time to let people in and to feel reasonably assured that people are safe there, no one is walking with guns," Boyce said.

Boyce said the public will likely see police around the country doing bag searches, having a presence at high altitudes to monitor crowds and deploying drones at mass events.

"It's not something that's invasive. [With] so many of these things, the priority here is to keep people safe," Boyce said.

Police can try to also stop people who are carrying weapons by using security checkpoints, with the intention that many others will choose not to go through the checkpoints, thinking they would be stopped and turned away, Boyce said.

"You want people walking by police officers, [before] going through gates into a frozen area," Boyce said.

He said it is also important to have an exit strategy to allow people to safely leave the event.

"You can't over-deploy this thing — you have to bring as many resources as you can into the situation. I've been in these things, I've been in championship parades … in Manhattan and you bring all your resources to bear at that point. And you have critical times there, critical times when these celebrities are going down the street and also when they call it quits," Boyce said in another interview on ABC News Live.

"You have to be fully on point, fully plugged into what's going on," Boyce said.

Securing side events

Another expert says events that draw massive audiences can be difficult to secure, but the celebratory parade is not something that is planned for in advance.

"Mass gatherings have been the primary target that is most vulnerable and most concerning, from a security standpoint," said Elizabeth Neumann, a former Homeland Security official and ABC News contributor, in an interview on ABC News Live.

The security preparations for the Super Bowl started 18 months ago with dozens of law enforcement agencies involved at the federal, state and local level to make sure the event goes on safely, according to Neumann.

"When you have side events that lead up to that massive event of the Super Bowl and the events after it — like the parade — those are actually also very concerning targets of opportunity but even harder to secure because you don't actually have the time to prepare — you don't get 18 months and you also don't get the same amount of federal resources to be able to secure an event," Neumann said.

"To the security community, we are more concerned about those side events because they just don't have as much time for preparation and we don't have as many resources toward securing it," Neumann said.

Being able to stop mass shooting incidents from happening is "the trouble that we are facing throughout our society right now," Neumann said.

"Unfortunately tragic events like this continue to happen in our country," Neumann said.

"The fact that you had individuals with guns in a mass crowd is very very concerning," Neumann said. "We need to do better to make sure that individuals aren't able to infiltrate such a large gathering."

Gun violence is a greater issue

Neumann said that gun violence in its entirety needs to be addressed and cannot just be on law enforcement to address.

"We certainly can describe the environment we have been living in for nine or 10 years now, where we are in an epidemic of mass attacks that are perpetrated for a variety of reasons, some with very cohesive ideological motives, some with no discernible motive whatsoever, and some are just spillover violence of individuals who are angry for some reason," Neumann said.

"When you are in that very difficult threat environment it is just an impossible scenario for law enforcement," Neumann said.

Despite planning and a heavy presence on the ground, gun violence is a deeper issue that needs a proactive solution.

"I thought the police chief did a wonderful job of pointing out how well prepared they were, the number of law enforcement that were on the scene and that they were running toward the threat," Neumann said.

"Especially after Uvalde where we did see law enforcement failure, it is important to point out how frequently our law enforcement officers are the ones running toward the threat. They are trying to protect the public and yet this keeps happening and it does remind all of us that this is a society-wide problem that we can't just rely on law enforcement to fix for us," Neumann said.

"We need to have some tough conversations, why do we keep ending up with these tragedies why do we have too many people who believe that violence is the solution to whatever their problems are," Neumann said.