A police officer who was on duty at a Florida high school and did nothing to stop gunman Nikolas Cruz when he started his massacre has been suspended.

Deputy Scot Peterson, who was armed with a handgun, didn't follow police procedure and immediately confront Cruz when he started his rampage killing 17 people with an AR-15 assault rifle, according to the Broward County Sheriff's department.

Instead he took cover at Marjory Stoneman Douglas High School for upwards of four minutes and 'never went in ', according to Sheriff Scott Israel who said Peterson's actions left him 'Sick to my stomach. There are no words.'

Israel added that the school resources officer should have have 'gone in, addressed the killer and killed the killer.'

The revelations come amid an intensifying debate about how to deal with school shootings, with many including President Trump and the NRA arguing that armed guards and teachers can 'instantly' take down gunmen.

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Scot Peterson is seen speaking at a February 2015 school board meeting Peterson

Scot Peterson, the school's resource officer, did not confront the gunman and instead stood positioned outside the school during the massacre, Broward County Sheriff Scott Israel (pictured right) said Thursday

He 'never went in,' Israel explained, citing security footage, and adding that he was armed and in uniform when bullets started to rain. Pictured are students embracing after the shooting

And in an interview with the New York Times, Coral Springs Officer Burton revealed Peterson hid from Cruz when the teenager started shooting. Pictured are students being treated after the shooting on Valentine's Day

It took about 30 minutes after the gunfire started for police to track Cruz down. He is pictured with his public defender in his first court appearance last week

WHAT ARE SCHOOL RESOURCE OFFICERS? Scot Peterson resigned from his position as the School Resource Officer at Marjory Stoneman Douglas High School on February 22 after it was revealed he did nothing to prevent the massacre a week earlier. School Resouce Officers (SROs) have been used in the United States since the 1950s as a liaison between local police offices and public schools, and to prevent crime on campus. They are defined by the US Justice Department as: sworn law enforcement officers responsible for safety and crime prevention in schools. The first SRO was put in a school in 1953 in Flint, Michigan, according to the Inter Faculty Organization. In the 1970s the officers became more common with the emergence of anti-drug and anti-gang programs, according to WBC News. Between 1975 and 2008 the use of SROs in American schools rose by 40 per cent. Advertisement

Peterson, who is 54 years old and a veteran of the force, resigned when he was informed of his suspension and will qualify for his pension.

And in an interview with the New York Times, Coral Springs Officer Tim Burton revealed Peterson hid from Cruz when the teenager started shooting.

Burton said Peterson 'was seeking cover behind a concrete column leading to a stairwell,' because he was worried Cruz could be lurking in the lot. He said Peterson couldn't hear gunshots or screams to lead him to the precise location of the shooting.

Even more shocking was the revelation that Peterson had been told in 2016 about Cruz's Instagram posts about opening fire at a school.

Call logs released by the Sheriff's Office show that on February 6 of that year, a neighbor's son called police and told them Cruz 'planned to shoot up the school on Instagram'.

The deputy who responded determined Cruz had knives and a BB gun and the information was forwarded to Peterson.

Israel said Peterson resigned when he was told he was being suspended without pay while police conduct an internal investigation, NBC Los Angeles reported. He said the cop said he'd met the requirements for retirement.

'After seeing video and witness statements, and Peterson's own statement, I decided this morning... to suspend Scot Peterson without pay pending an internal investigation,' Israel said.

He said the video shows Peterson arrive at Building 12, where most of the killing took place, and take position outside the school.

Apart from getting 'on his radio' to alert police of the situation, Peterson did 'nothing' to prevent 17 innocent people, including 14 children, from being slaughtered, Israel said.

Israel said that instead of just standing there, Peterson should have gone 'in, addressed the killer and killed the killer,' adding that instead he 'stood outside for upwards of four minutes.'

He said that Peterson's lack of action left him 'devastated. Sick to my stomach. There are no words.' As Israel spoke there were tears in his eyes and he 'appeared emotional.'

Peterson never discharged his gun during the shooting.

But according to him, he did his duty.

Peterson was reportedly 'distraught' about the deadly shooting, but 'believed he did a good job,' president of the Broward Sheriff's Office Deputies Association said.

'He believed he did a good job calling in the location, setting up the perimeter and calling in the description [of Cruz],' Jim Bell told the New York Post.

His pension will be 75 per cent of the average of his top five earning years while on the job, Bell said.

He also said that thought he didn't want to second-guess Patterson, he thinks not going after Cruz was a mistake.

'We have to act, even if that means risking our lies to save many, many more lives,' he said.

The first photograph of Peterson was tweeted by CBS producer Marty Lebel.

It came from a February 2015 school board meeting in which Peterson discussed incidents at Atlantic Terminal College in Coconut Creek, where he was given housing from around 2000.

He told the board: 'I’ve been a police officer for 30 years and I’ve been a school resource officer for 25 years.'

He described receiving a call alerting him to an alarm in the school's cafeteria.

He said: 'And right there I knew, because I’ve been at that school for many years, I knew right when I heard the cafeteria, you know when you get the hairs on the back of your neck going up, I said, "that never goes off".

'So I ran into my trailer, I grabbed my firearm and my ID and my shorts and my sneakers and I ran over to the cafeteria. As I got to the cafeteria, sure enough, there were four males inside the cafeteria.

'They saw me peaking through the glass, they obviously fled. I chased them, I’m getting older, but I started chasing them, I identified who I was and as ironic as it may seem, they ran right towards my trailer. So they ran past, jumped over the fence, I jumped into my car, I apprehended two of them… threw them in the back, kept going, grabbed the other two.'

He described another 'chilling' incident when he heard banging on the front door and a facilities lady was there screaming.

She said there was a man dressed all in black wearing a ski mask and armed with a gun.

'So I ran, put some shorts on, ran out with my firearm, while I’m running to the school, I'm contacting Coconut Creek Police, we set up a perimeter. Long story short, we caught the individual when he ran across the Coconut Creek Parkway and he was hiding near a bank.'

It was, however just an 18-year-old senior with a paintball gun.

Peterson, who appears to be large in stature in a video of the meeting, also admitted: 'I’m almost on my way out, I’m 30 years...'

Call logs released by the Sheriff's Office show that on February 6 of that year, a neighbor's son called police and told them Cruz 'planned to shoot up the school on Instagram'

Peterson told the board: 'I’ve been a police officer for 30 years and I’ve been a school resource officer for 25 years'

He had been investigated by his department twice before last week's shooting - once in 2015 when he wrote an email about the Resident On Campus Security Program. This is the same topic he discussed at the school board meeting.

Around the time, officers were fighting to keep their mobile homes on school grounds.

In it, he questioned the management of Chief Anthony Williams of the Broward District School Police.

He was alleged to have not used common sense and good judgement in authoring the email, according to internal affairs reports in his personnel file.

It was recommended he be counselled, according to USA Today.

In another incident he was investigated in 1994 for his conduct, but it was unfounded and dropped.

When last week's attack ended Cruz managed to ditch his semiautomatic AR-15 and slip away on foot. Within about seven minutes from when the gunfire began he was out of the school and in a nearby neighborhood where he was ultimately stopped by an officer from a neighboring police department.

The first officers to enter the school did so roughly 10 minutes after gunfire started, but at that point Cruz had already escaped.

It took about 30 minutes after the gunfire started for police to track Cruz down. After that it took an additional 15 minutes for police to identify him. Many students were still cowering behind locked doors for 45 minutes after the attack started, unsure if the person banging on their classroom doors was the shooter or the police.

Peterson started working as a resource officer Stoneman Douglas in 2009, according to the Sun-Sentinel. He was responsible for investigating crimes related to stolen property, assault and narcotics offenses.

Peterson is believed to be a divorced father-of-four; it's not clear if he ever remarried. He started working for the sheriff's office in 1985, and in 2016 made $75,673.72 annually, records show.

The Palm Beach County Sheriff's office is reportedly providing protection to Peterson and his family after a request. He now lives in Boynton Beach, and a neighbor, Nelson Sandy, told the Sun Sentinel he saw Peterson leave his home around 3pm Saturday flanked by two officers.

'They were here today, three police officers and they all left together,' he said.

In 2014, Peterson was presented with the title of School Resource Officer of the Year for the City of Parkland District by the Broward County Crime Commission because he proved 'to be reliable in handling issues with tact and judgment.' He'd been with the school for five years at that point.

The press release for the award also says Peterson was active in 'mentoring and counseling' the students at Stoneman Douglas.

Peterson was nominated for Parkland deputy of the year in 2017, according to an internal memo from the sheriff's office. He was called 'a dedicated SRO who values his position and takes pride in protecting the students, faculty and staff at his school.'

In 2013 Peterson was also named Broward County Sheriff Parkland employee of the year.

Two years later he was featured in a Sun-Sentinel article arguing the importance of SROs on school grounds, fighting for them to keep their jobs and perks when a Florida audit showed they were unnecessary.

'These colleagues work hard,' he is quoted as saying when told the scheme did not prevent crime.

'We are crime prevention, an audit report will never show how much we prevent.'

And in an interview with the New York Times , Coral Springs Officer Tim Burton revealed Peterson hid from Cruz when the teenager started shooting. Burton, who used to be a professional baseball player, said Burton hid behind a concrete column

Broward County Sheriff Scott Israel (pictured Wednesday night) said the school's resource officer Scot Peterson has been suspended without pay as police conduct an internal investigation, reported NBC Los Angeles

He said Peterson was positioned outside the school, adding that he was armed and in uniform during the shooting. But when he heard the gunfire begin, he 'never went in,' Israel explained, citing security footage. Students are pictured the day after the fatal massacre

Israel said that instead of just standing there, Peterson should have 'went in, addressed the killer and killed.' Students are pictured with their hands over their heads as they evacuate Marjory Stoneman Douglas High after the shooting

During Thursday's conference Israel also addressed prior calls officers in Broward had received related to the gunman, many of which pointed to his instability and likelihood to carry out the crime he did.

Since 2008, the agency received 23 calls about Cruz and his brother Zachary.

He said two officers who previously responded to one of those calls, Edward Eason and Guntis Treijs, have been placed on restrictive duty.

'In two of the cases, after being briefed by internal affairs I've restricted two of our deputies to take statements and make a decision to see whether they should have and could have,' done something to prevent the Parkland tragedy, Israel explained.

'Our main goal at this point, absent of helping these families heal and keeping our schools safe, is making sure this killer receives the justice he deserves,' Israel said prior to Thursday's press conference.

Israel also announced Wednesday that he has directed a new policy that will see Broward County deputies armed with rifles, including AR-15s, and stationed at schools. He said he does not support arming teachers.

Cruz has been charged with 17 counts of murder after Thursday's shooting.

He had previously been reported to police and FBI agents on multiple occasions due to his disturbing behavior at school and on social media, and particularly regarding his affliction with weapons.

Teenagers wore their football jerseys to Feis's funeral in Coral Springs, Florida, on Thursday morning

Former students and police officers also attended the service where Feis was eulogized as 'one of the greatest people' they all knew

On Thursday afternoon grieving teenager football players wore their jerseys to the funeral of their hero coach who died saving students at the Parkland high school massacre.

Coach Aaron Feis, 37, died while acting as a human shield by lying on top of students at Stoneman Douglas High School while gunman Aaron Cruz was killed

Coach Aaron Feis, 37, died while acting as a human shield by lying on top of students at Stoneman Douglas High School while gunman Aaron Cruz was killed.

He was among three adults who died trying to protect the youngsters. Fourteen students were also slain.

On Thursday, mourners turned out en masse to attend Feis's funeral service in Coral Springs.

He was a former student of the school and had been teaching there for eight years.

Among the mourners was a student who said he had become a father figure to him.

'His time was infinite when it came to students and athletes,' Brandon Corona said.

Feis's friend Joe LaGuardia said he knew instinctively that he would have been trying to save lives when he heard about the shooting.

'There wasn't a question in my mind that after I finished Ash Wednesday service I had to go and check out Aaron's Facebook page or get ahold of the family because I know that Aaron would be running to save lives, I just knew it.'

'He was one of the greatest people I know.

'I knew that the inspiration that his family and his wife gave him was the strength that allowed him to make a decision in split second in order to give his life over to his students in order to save them, even if it was only three students or a half dozen students.

'That was the Aaron I know,' he said.

Sheriff Israel was among those who spoke at the service.

He knew Feis before tragedy struck the school last week and remarked on how every football coach kept him on as an assistant.

Some of the students wore ties beneath their Eagles jerseys. Others found comfort in one another and were able to smile through the morbid occasion