(CNN) JAKE TAPPER, CNN ANCHOR: Hello. I'm Jake Tapper in Washington, where the state of our union is still raw in the wake of the tragedy in Florida.

President Trump and Florida's Republican governor have promised action, including some proposals to change existing gun laws. And a brand-new CNN poll now shows support for stricter gun purchasing laws at its highest level of the last 25 years, with 70 percent now saying that they back new, more restrictive gun legislation.

Nearly two-thirds think government and society can take action that will effectively prevent future mass shootings. That's much higher than CNN polls after the tragedies in Las Vegas, and Orlando, and Charleston, and Sandy Hook, suggesting perhaps, perhaps the shooting in Parkland, Florida, has shifted public opinion in a way other incidents have not.

But there are also new questions about the numerous missed red flags about the shooter and the immediate response. Coral Springs sources tell me, in addition to the school resource officer, when Coral Springs arrived on the scene, they were surprised to find three other Broward County sheriff's deputies who had not yet entered the school.

The Broward County denies those reports, saying only one deputy was there during the time of the shooting, while the shooter was there. But what about in its immediate aftermath, when it was still an active shooter situation and victims were in desperate need of help?

Joining me now to discuss all of this is Broward County Sheriff Scott Israel.

Sheriff, thanks so much for joining us. I appreciate it.

I want you to take a listen to Stoneman Douglas senior Brandon Huff talking about your deputy, the school resource officer, Scot Peterson.

(BEGIN VIDEO CLIP)

BRANDON HUFF, SENIOR, MARJORY STONEMAN DOUGLAS HIGH SCHOOL: The school resource officer was behind a stairwell wall just standing there, and he had his gun drawn. And he was just pointing it at the building.

And you could -- shots started going off inside. You could hear them going off over and over. And he was just talking on the radio, and he never did anything for four minutes. And he's the only one with a gun. He's wearing a bulletproof vest. And all -- he has all that, while school security guards, you know, coaches pretty much, were running in shielding kids.

(END VIDEO CLIP)

TAPPER: Sheriff, how do you respond to this student?

BROWARD COUNTY SHERIFF SCOTT ISRAEL: Oh, what the student said, our video and audio and all the witness statements we have taken corroborates that.

That's what I saw. And when I saw that, I was disgusted. I was just demoralized with the performance of former Deputy Peterson. And that's why I called him in and suspended him without pay, as we were going to move towards termination. And he resigned.

TAPPER: Did he tell you why he didn't go in?

ISRAEL: He did not.

TAPPER: I'm also told by sources in Coral Springs that Coral Springs police who arrived at the scene saw that three other Broward deputies were standing behind cars, not having gone into the building. What can you tell me about that?

ISRAEL: Well, let me perfectly clear.

Our investigation to this point shows that, during this horrific attack, while this killer was inside the school, there was only one law enforcement person, period, and that was former Deputy Scot Peterson.

Coral Springs arrived. A group of Coral Springs officers went in within, I think, about four minutes, we're projecting, after the killer left the campus.

The -- I understand that they're going to give statements to us regarding the other three, four, five deputies. At this point, we have no reason to believe that any one acted incorrectly or correctly. That's what an investigation is.

Everybody's entitled to their own opinion, but nobody's entitled to their own set of facts.

We do know, Jake, that Deputy Peterson at the time uttered -- he disseminated information over the police radio. We don't know why those deputies -- what those deputies heard. Perhaps they did something by what they heard from Peterson.

And that will be, you know, outlined in interviews. We will get to the truth. But, at this point, one deputy was remiss, dereliction of duty, and he's now no longer with this agency. And that's Peterson.

TAPPER: And you're saying -- you're saying that because, during the time that the shooter was in the school, you say Peterson was the only one there.

But that's not -- that wasn't known at the time. You know that now because of security cameras. You saw when he left the school.

ISRAEL: Correct.

TAPPER: This is after the fact.

But when did your deputies, not Peterson, but the others, when did they arrive on the scene, because Coral Springs sources say, when Coral Springs arrived, there were Broward deputies there in addition to Peterson.

ISRAEL: And I don't dispute that, but that is an active investigation. We have not taken statements yet from the Coral Springs officers.

We found out, I believe, five or six days ago from their police chief that he told one of our colonels about the -- about the information. We're going to be taking statements from those Coral Springs police officers.

Then we're going to be speaking with our deputies. If any deputies are alleged to have dereliction of duty, we will look into that. We don't know what the deputies heard on the radio. Coral Springs and the Broward Sheriff's Office, we have different radio systems.

So, we don't know what one was hearing vis-a-vis what the other was hearing. All I can tell you is, we will investigate every action of our deputies, of their supervisors. And if they did things right, we will move forward. And if they did things wrong, I will take care of business in a disciplinary matter, like I did with Peterson.

TAPPER: And just so people watching at home understand, even after the shooter left the school, there was a period of time where nobody was going into the school, no law enforcement officers. People were bleeding out.

The question -- nobody knew that the shooter had left the school, so officers needed to go in. One of the things that we have heard -- and I don't know if this is true or not -- I can -- hope you can shed light on it -- is that there might have been a stand-down order, somebody on the radio telling Broward deputies not to enter this school until a SWAT team arrived.

What can you tell us about that?

ISRAEL: I can't tell you anything about that. I haven't heard that.

As I said, we feverishly are dissecting. It's a voluminous investigation. We're taking hundreds and hundreds of statements. And, right now, Jake, the focus of this agency is on the successful prosecution of the killer.

So, we're doing that. Our detectives have worked tirelessly. We will investigate all aspects of this case. We will look at all the actions or inactions of every single deputy and leader on our agency, sergeants, lieutenants, captains. And we will make some decisions.

But, right now, all I can tell you is, during the killing, there was -- while the killer was on campus with this horrific killing, there was one deputy, one armed person within proximity of that school. And that was Peterson.

Everything else is fluid. And, as I said, we will get to the truth. But, right now, people could have conjecture, people could act on rumors, and people have -- you know, everybody has the right to their own opinion, but nobody has the right to their own set of facts.

TAPPER: Have you listened to the...

ISRAEL: The facts will come out.

TAPPER: Have you listened to the radio recordings?

ISRAEL: I'm not, but the investigators are, of course.

TAPPER: OK. But you haven't. You have not heard them, though?

(CROSSTALK)

ISRAEL: No.

But what they're doing now is, they're marrying up the audio with the visual. And I was told that one of the -- one of Peterson's utterances on the radio, I think one or two times, he actually says shots fired.

So, you would have to assume at that time every person who heard that transmission is pushing as fast as they can, code three, as we call it, to the school, to the school. Identify the threat. Neutralize the target. Take the killer out.

There comes a point in time later that Peterson makes a transmission that would almost lead one to believe that he's talking about perimeters.

So, if I know my school resource deputy is talking about perimeter positions, it's absolutely safe to assume, incorrectly, if that's what actually happened, it's absolutely safe to assume that, if a person there is talking about perimeter, that perhaps he sees the killer leaving, and -- and you're going to a perimeter position to catch the killer.

But I don't know what was in the mind of the other deputies. I don't know what was in the mind of Peterson. This is why we investigate. All I can tell you is that...

TAPPER: Right.

ISRAEL: ... from the time I heard about this, I did what needed to be done with former Deputy Peterson.

TAPPER: But, Sheriff, the Thursday -- the day after the horrific incident, at a vigil, the city manager for Coral Springs confronted you in public.

And one of the things he confronted you about, sources tell me, is the idea that your deputies did not go into the school while children inside were bleeding out.

ISRAEL: That's absolutely untrue.

We had a conversation. We were out in public. The only two people who could have heard the conversation were myself and the city manager. It was a conversation. I'm not going to share that conversation. It was very short.

The city manager and I have spoken numerous times. We have met. He's a great city manager. He does a great job with Coral Springs.

TAPPER: OK.

ISRAEL: We have got a great relationship. And it was just two guys having a conversation.

TAPPER: One of the questions about the response by Broward is whether this was policy to set up a perimeter, instead of going in.

Earlier this week, you seemed to suggest that your deputies are trained to arrive and not immediately go into the site of the shooting, but rather to create a staging area.

Listen to yourself a few days ago talking about what you learned from the Fort Lauderdale Airport shooting 13 months ago. Take a listen.

(BEGIN VIDEO CLIP)

ISRAEL: One of the key lessons we learned from the airport was the phenomenon of self-dispatching and not allowing deputies and police officers from all over the tri-county area to just arrive haphazardly.

And we had staging areas and people who came, went to a staging area. And they were inserted into the position in a commonsense way, and everybody had a job to do.

(END VIDEO CLIP)

TAPPER: See, that seems to -- that sounds to a lot of people like the opposite of what police forces learned after Columbine, which is, when you arrive, you don't wait; you run in.

(CROSSTALK)

ISRAEL: I'm glad you asked that question.

Jake, you're completely talking apples and oranges. And I'm glad you brought that up.

When we have a horrific incident of any magnitude, and the incident is over, and people are arriving to help, and we know we have five, 10, 12 hours of work to do, we have our deputies, police officers, firefighters go to staging areas, so we can insert them in a clear and concise manner into the scenario, into the event.

An active shooter is completely different. As people were coming to the airport, we didn't have an active shooter. He was already in custody 72 seconds after the event.

This is an active shooter. We push to the entry, to the killer. We get in, and we take out the threat. Completely different set of circumstances.

TAPPER: OK.

Sheriff, when did you find out that Deputy Peterson had not gone into the building? How soon after the shooting did you know that?

ISRAEL: Not for days. We -- our investigators looked...

TAPPER: How many days?

ISRAEL: I'm not sure.

TAPPER: Because you spent much of the Wednesday night town hall on CNN, with the entire Stoneman Douglas community, students and teachers and parents, attacking the NRA, saying that police need more powers, more money to prevent future tragedies.

You didn't disclose any of this to the crowd then, the Stoneman Douglas High School community. Did you know it then? Did you know it Wednesday night?

ISRAEL: It was spoken about during that -- earlier during that day.

I'm not on a timeline for TV or any news show. We need to get it right. We need to get it accurate. We're talking about people's lives. We're talking about a community. We need to corroborate, we need to verify.

And once we did the next day, and I looked at the tape, and I was 100 percent certain that it happened the way I was told about the investigators initially told me -- told about, I didn't even release it right that second.

(CROSSTALK)

TAPPER: You didn't look at the video? One week after the shooting, you hadn't looked at the video yet?

ISRAEL: I looked at the video as soon as our investigators -- it wasn't my job to look at the video. It was investigators' job to look at the video.

I'm still sheriffing this county. There were many things to do. We have investigators, homicide investigators, internal affairs investigators dissecting it. And when they felt there was a video that -- ready for my view, that I might take action on one of our deputies, I looked at the video.

And let me add this, Jake. Once I saw the video, the first order I gave was for our detectives to notify the families that the -- of the -- those lost, the families. Yesterday, today and tomorrow, the families come first. And I wanted to make sure the families knew what happened and what was about to happen before we released...

(CROSSTALK)

TAPPER: The families were at the CNN town hall, sir. Sir, the families were at the CNN town hall. And you could've disclosed to them...

ISRAEL: That's not the -- that's not -- I couldn't disclose it then, because there was no corroboration, Jake. There was no confirmation.

We needed to dot I's and cross T's. And I certainly would not disclose it to a family at a town hall. Not every family was there. One of the families, one -- Mr. Pollack had gone to Washington, D.C.

TAPPER: All right.

ISRAEL: That's not the way you do things, over a news camera. You do it individually. You meet privately with families. You have compassion. You don't do it at a public forum. And we weren't ready to do it anyway.

TAPPER: Right. But your tone -- your tone at the public forum, sir -- your tone at the public forum was rather belligerent towards the NRA.

And you were talking about needing more police protection -- I mean, more police funding and more police powers, and yet you knew...

ISRAEL: That's not...

TAPPER: No, it's not -- that wasn't your tone?

ISRAEL: That's not true. Jake, that's not true at all.

I wasn't belligerent towards the NRA. I took a passionate stance, as I always have, about commonsense gun reform and expanding police ability throughout our country when we come in contact with someone mentally ill to take them to a facility.

TAPPER: OK.

ISRAEL: To take guns away from them.

There was no belligerence at all. And I completely disagree with you.

TAPPER: A medical -- let's talk about the response.

A medical first-responder told local news station WSVN that medical personnel were asking to go into the school, but law enforcement wouldn't let them. He told WSVN -- quote -- "Everything I was trained on mass casualty events says they did the wrong thing. You don't want wait for the scene to be cleared. You go in immediately, armed, retrieve the victims. You can't leave the victims laying there."

What's your response to that, sir?

ISRAEL: I agree with that. That's very accurate.

That is how -- this is what you do. Once the killer leaves the scene of a mass casualty, it's still an active killer scene. There are people wounded, people that could -- lives could be saved.

And let me say this. Coral springs police, Broward sheriff's deputies, we did carry people out there. These deputies and these -- and the Coral Springs police officers are credited with savings quite a few lives by getting people medical attention. So, we did.

TAPPER: But did you prevent medical people from going inside?

ISRAEL: No.

Once the scene -- once the scene is -- medical people wouldn't go inside until you're sure that they're not going to get killed inside. We have -- what we do is we tell...

(CROSSTALK)

TAPPER: But this person told WSVN -- this person told WSVN he wanted to go in, this medical personnel, emergency first-responder wanted to go in and wasn't allowed to.

ISRAEL: Jake, I'm hearing that for the first time. If you know who the person is, please have him contact me or the Broward Sheriff's Office, and we will interview him, we will take statements from him.

And if that's true, that's certainly something we will look into, but I'm hearing this for the first time.

TAPPER: OK. WSVN will get back to you, I'm sure.

Let's talk about the missed red flags. We now know at least 18 calls were made to the Broward County Sheriff's Office related to the shooter prior to the shooting. Let's talk about them.

In February 2016, your office received a call that the shooter made a threat on Instagram to shoot up a school. One of your deputies responded and, according to your records released, the information was forwarded to Deputy Peterson at the school.

What, if anything, was done with that information?

ISRAEL: I'm not sure if anything was done with that information.

I do know as far as notifying the person or notifying either Palm Beach Sheriff's Office or one of the local jurisdictions, depending on where the killer was living at the time.

But Peterson did, I think, report Cruz to DCF, if I'm not mistaken. He did get -- receive medicine. He did get medical treatment. And, as I said, of those 18 calls, two of those calls are being -- 16 of them, we believe, were handled exactly the way they should. Two of them, we're not sure if our deputies did everything they could have or should have.

That's not to say they didn't. That's not to say they did.

(CROSSTALK)

TAPPER: Which are the two that you're looking in to?

ISRAEL: One was the call from a woman in Massachusetts. And the other one escapes me right now. But we're looking into those two calls.

We will absolutely find out what we did or what we didn't do and -- as I said in a press conference a few days ago, and we will handle that accordingly.

(CROSSTALK)

TAPPER: One of them, in September 2016...

(CROSSTALK)

ISRAEL: But let's not -- but hold on one second, Jake.

TAPPER: Yes.

ISRAEL: Let's not forget the whole crux of this is giving law enforcement, giving deputies, giving police officers, not only in Broward County, but in Florida and around the nation, expanded power to be able to do something more than just write a report.

That's the whole reason I went on CNN for the town hall meeting.

(CROSSTALK)

TAPPER: Sir, isn't making a threat against a school a crime?

ISRAEL: Not if the person doesn't have the ability to carry it out.

You could say, a nonspecific threat, I'm going to go to a school. It's not a crime. We need it to be a crime, or at least we need to be able to say, if a person makes a nonspecific threat with -- what an assault is, is a threat, coupled with the apparent ability to carry it out.

If the person doesn't have the apparent ability to carry it out, it's not a crime.

(CROSSTALK)

TAPPER: Well, in September 2016, the shooter indicated he wanted to guy a gun.

Deputy Peterson knew about that. He initiated the report. The school launched a threat assessment. At this point, you have somebody saying that they're going to shoot up a school and somebody with a gun. That's not enough?

ISRAEL: That's not enough. And that's what we're trying to change.

We're trying to change the law, so we can either arrest that person, or, more importantly, get that person to a medical facility, because if you arrest the person, there's going to be a time where they get out of jail anyway.

We want to get people medical help for mental illnesses, continual medical help. And then when they get out of the medical facility and a doctor says they're better, that doesn't mean they're better. That means they're rehabbing.

We want to be able to take their guns away from them for a long, long period of time. And that's what the governor is going to be -- Governor Scott is going to be introducing his proposal. I have read it. And it's a giant, giant step in the right direction. And we're hoping that...

TAPPER: Well, Sheriff, how about this? How about this?

In November, the Palm Beach Sheriff's Office, not your office, but a neighboring office, responded to a call from a woman who had taken the shooter in and his brother after the death of their mother. She told police that the shooter had gotten into a physical fight with her son and threatened to go get his gun and come back.

She also said he had used guns to threaten people before and had put a gun to others' heads in the past. That's a crime. Were you aware of that incident?

ISRAEL: No, I wasn't aware of that incident.

But putting a -- if a person had a gun put to their head, and they were the victim of that type of incident, that's an aggravated assault. That's an absolute felony. That is a crime.

And a person should be arrested for that. I don't know if the victim wanted to cooperate. I don't -- it was in Palm Beach County. I don't know the nuances and the specifics of the case. But that absolutely is a crime.

TAPPER: On November 30, fewer than three months ago, your office received a call saying from a tipster explicitly saying that Cruz could be a -- quote -- "school shooter in the making."

According to notes released on that call, no report was even initiated. At this point, sir, do you understand how the public, seeing red flag after red flag after red flag, warning after warning after warning, they hear that your office didn't even initiate a report when they got a call saying that this guy could be a school shooter in the making?

How could there not even be a report on this one?

ISRAEL: Well, if that's accurate, Jake, there needed to be a report. And that's what we're looking into, that a report needed to be completed, it needed to be forwarded to our either homeland security or violent crimes unit, and they would've followed up on it.

(CROSSTALK)

TAPPER: That's from your notes. That's from notes released by your office. I'm not making this up. This is from Broward...

ISRAEL: No.

And that's -- and that's what -- that's -- the officer who handled that is on restrictive duty. And we are -- that's an active internal investigation. And we are looking in to it.

I can't tell you -- I can't predict how an investigation is going, but we have -- I have exercised my due diligence. I have led this county proudly, as I always have. We have restricted that deputy as we look in to it.

Deputies make mistakes. Police officers make mistakes. We all make mistakes. But it's not the responsibility of the general or the president, if you have a deserter. You look into this. We're looking into this aggressively. And we will take care of it, and justice will be served.

TAPPER: Are you really not taking any responsibility for the multiple red flags that were brought to the attention of the Broward Sheriff's Office about this shooter before the incident, whether it was people near him, close to him calling the police...

(CROSSTALK)

ISRAEL: Jake, I can only -- Jake, I can only take responsibility for what I knew about. I exercised my due diligence.

I have given amazing leadership to this agency.

TAPPER: Amazing leadership?

ISRAEL: I have worked -- yes, Jake.

There's a lot of things we have done throughout this -- this is -- you don't measure a person's leadership by a deputy not going into a -- these deputies received the training they needed. They received the equipment.

TAPPER: Maybe you measure somebody's leadership by whether or not they protect the community.

In this case, you have listed 23 incidents before the shooting involving the shooter, and still nothing was done to keep guns out of his hands, to make sure that the school was protected, to make sure you were keeping an eye on him.

ISRAEL: Jake...

(CROSSTALK)

TAPPER: Your deputy at the school failed.

I don't understand how you can sit there and claim amazing leadership.

ISRAEL: Jake, on 16 of those cases, our deputies did everything right. Our deputies have done amazing things.

We have taken this -- in the five years I have been sheriff, we have taken the Broward Sheriff's Office to a new level. I have worked with some of the bravest people I have ever met.

One person -- at this point, one person didn't do what he should have done. It's horrific. The victims here, the families, I pray for them every night. It makes me sick to my stomach that we had a deputy that didn't go in, because I know, if I was there, if I was on the wall, I would have been the first in, along with so many of the other people.

TAPPER: I think there are a lot of people, sir, who think that there are a lot of mistakes, other than that one deputy.

But let me ask you something else. A lot of people in the community have noted that the Broward County School Board entered into an agreement when you were sheriff in 2013 to pursue the -- quote -- "least punitive means of discipline" against students.

This new policy encouraged warnings, consultations with parents and programs on conflict resolution, instead of arresting students for crimes.

Were there not incidents committed by the shooter as a student had this new policy not been in place that otherwise he would have been arrested for and not able to legally buy a gun?

ISRAEL: What you're referring to is the PROMISE Program.

And it's giving the school -- the school has the ability under certain circumstances not to call the police, not to get the police involved on misdemeanor offenses and take care of it within the school. It's an excellent program.

It's helping many, many people. What this program does is not put a person at 14, 15, 16 years old into the criminal justice system.

TAPPER: What if he should be in the criminal justice system? What if he does something violent to a student? What if he takes bullets to school? What if he takes knives to schools? What if he threatens the lives of fellow students?

ISRAEL: Then he goes to jail. That's not applicable in the PROMISE Program.

TAPPER: That's not what happened. But that's not what happened with the shooter.

ISRAEL: If -- Jake, you're telling me that the shooter took knives to school or bullets to school, and police knew about it?

TAPPER: I don't know if police knew about it.

ISRAEL: No. Well, police...

TAPPER: I know that the agreement that you entered into with the school allowed the school to give this kid excuse after excuse after excuse, while, obviously...

ISRAEL: Not for bullets, not for bullets, not for guns, not for knives, not for felonies, not for anything like that. These are infractions within the school, small amounts of marijuana, some misdemeanors.

You're absolutely exacerbating it. That's not...

(CROSSTALK)

TAPPER: There are at teachers at the school had been told, if you see Cruz come on campus with a backpack, let me know.

Does that not indicate that there is something seriously awry with the PROMISE Program if these teachers are being told, watch out for this kid, and you don't know about it?

ISRAEL: We don't know that that has anything to do with the PROMISE Program. I didn't hear about this until after the fact. I have heard about this information about a week ago. I do know about it. I don't know who the teacher was. It hasn't been corroborated, but that has nothing to do with the PROMISE Program.

I can't, nor can any other Broward sheriff's deputy, handle anything or act upon something you don't know about it. There's no malfeasance or misfeasance if you don't know about something.

TAPPER: He asked a question at the town hall of you. So, you can find him if you want.

I have one last question for you, sir. Florida State Representative Bill Hager from Boca sent a letter to the governor of Florida, Rick Scott, yesterday asking him to remove you for negligence of duty and incompetence.

Here's what he wrote -- quote -- "An investigation by Sheriff Israel into the unfathomable inaction of these deputies will do nothing to bring back the 17 victims. The sheriff was fully aware of the threat this individual presented to community and chose to ignore it."

What is your response? And will you resign?

I never met that man. He doesn't know anything about me. And the letter was full of misinformation. I wrote a letter back to the governor. I talked about all the mistakes that Hager in his letter. It was a shameful, politically motivated letter that had no facts.

And of course I won't resign.

TAPPER: The last question, sir. Do you think that if the Broward Sheriff's Office had done things differently, this shooting might not have happened?

ISRAEL: Listen, ifs and buts and candy and nuts, O.J. Simpson would still be in the record books.

(CROSSTALK)

TAPPER: I don't know what that means.

There's 17 dead people, and there's a whole long list of things your department could have been done differently.

ISRAEL: How could -- listen, that's what after-action reports are. That's for -- lessons-learned reports are for.

We -- I have entered into conversation with Chuck Wexler of the Police Executive Research Forum. They will be coming to town to do an independent after-action lessons-learned report.

We understand everything wasn't done perfectly. And if it happened in Los Angeles or Chicago or any other city, every person wouldn't have perform perfectly. That's not what happens.

Yes, if Scot Peterson went into -- do I believe in Scot Peterson went into that building, there was a chance he could have neutralized the killer and saved lives? Yes, I believe that.

But as far as anything else done at this point, I can't say that.

TAPPER: Well, we hope you get to the bottom of it.

ISRAEL: And I might say it -- what is that?

TAPPER: We hope you get to the bottom of it, sir. There are a lot of people wondering about a lot of questions.

ISRAEL: We will. We will. We will. We will.

And there's no timeline on it, other than to work as fast as we can. But we want to get it right. We want to get it accurate. When we come to the public, we want accurate information. And we're not going to push forward to meet the timeline of a show or a newscast.

TAPPER: All right. I appreciate it.

ISRAEL: Thank you.

TAPPER: And our thoughts and prayers are with the people of Parkland and Marjory Stoneman Douglas High School.

Thank you for being here and answering my questions, sir.

ISRAEL: You bet. Thank you for having me on.