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TOPSHOT - Marjory Stoneman Douglas High School staff, teachers and students return to school greeted by police and well wishers in Parkland, Florida on February 28, 2018. 
Students grieving for slain classmates prepared for an emotional return Wednesday to their Florida high school, where a mass shooting shocked the nation and led teen survivors to spur a growing movement to tighten America's gun laws. The community of Parkland, Florida, where residents were plunged into tragedy two weeks ago, steeled itself for the resumption of classes at Marjory Stoneman Douglas High School, where nearby flower-draped memorials and 17 white crosses pay tribute to the 14 students and three staff members who were murdered by a former student.
 / AFP PHOTO / RHONA WISE        (Photo credit should read RHONA WISE/AFP/Getty Images)
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TOPSHOT - Marjory Stoneman Douglas High School staff, teachers and students return to school greeted by police and well wishers in Parkland, Florida on February 28, 2018. Students grieving for slain classmates prepared for an emotional return Wednesday to their Florida high school, where a mass shooting shocked the nation and led teen survivors to spur a growing movement to tighten America's gun laws. The community of Parkland, Florida, where residents were plunged into tragedy two weeks ago, steeled itself for the resumption of classes at Marjory Stoneman Douglas High School, where nearby flower-draped memorials and 17 white crosses pay tribute to the 14 students and three staff members who were murdered by a former student. / AFP PHOTO / RHONA WISE (Photo credit should read RHONA WISE/AFP/Getty Images)
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This image made available by the Broward County Sheriff's Office on Sunday, Feb. 18, 2018, shows Sheriff Scott Israel, holding the hand of Anthony Borges, 15, a student at Marjory Stoneman Douglas High School. The teenager was shot five times during the massacre on Valentine's Day that killed 17 students. Borges is being credited with saving the lives of at least 20 other students. (Broward County Sheriff's Office via AP)
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This image made available by the Broward County Sheriff's Office on Sunday, Feb. 18, 2018, shows Sheriff Scott Israel, holding the hand of Anthony Borges, 15, a student at Marjory Stoneman Douglas High School. The teenager was shot five times during the massacre on Valentine's Day that killed 17 students. Borges is being credited with saving the lives of at least 20 other students. (Broward County Sheriff's Office via AP)
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(CNN) —  

An attorney for Stoneman Douglas High School’s former resource officer defended the officer’s response to the Parkland shooting, saying in a statement Monday that Scot Peterson acted “appropriate under the circumstances.”

Peterson, who was armed on campus, did not enter the school because he believed the shooting was coming from outside the school buildings, according to attorney Joseph DiRuzzo III.

“Let there be no mistake, Mr. Peterson wishes that he could have prevented the untimely passing of the seventeen victims on that day, and his heart goes out to the families of the victims in their time of need,” the statement from DiRuzzo says.

“However, the allegations that Mr. Peterson was a coward and that his performance, under the circumstances, failed to meet the standards of police officers are patently untrue.”

Peterson resigned on Thursday after Broward County Sheriff Scott Israel suspended Peterson without pay for allegedly waiting outside the Florida school as the shooting unfolded.

“What I saw was a deputy arrive at the west side of building 12, take up a position,” Israel said of the footage. “And he never went in.”

However, in the statement, DiRuzzo said that Israel’s statement “is, at best, gross over-simplification” of what happened when a shooter killed 17 people.

Peterson’s side

Peterson initially ran toward the 1200 building where the shooting took place, and then he “heard gunshots but believed that those gunshots were originating from outside of any of the buildings on the school campus,” according to DiRuzzo.

The Broward County Sheriff’s Office, or BSO, “trains its officers that in the event of outdoor gunfire one is to seek cover and assess the situation in order to communicate what one observes to other law enforcement,” DiRuzzo said.

Peterson acted consistent with his training and “took up a tactical position between the 700-800 buildings corridor/corner,” Peterson said. He was the first officer to advise dispatch that he heard shots fired, and he initiated a “Code Red” to lock down the campus, according to the statement.

“Radio transmissions indicated that there was a gunshot victim in the area of the football field,” which served to confirm Mr. Peterson’s belief “that the shooter, or shooters, were outside,” according to DiRuzzo’s statement.

DiRuzzo’s statement argues that Sheriff Israel jumped to an unfounded conclusion and then publicly criticized Peterson’s actions.

“Mr. Peterson is confident that his actions on that day were appropriate under the circumstances and that the video (together with the eye-witness testimony of those on the scene) will exonerate him of any sub-par performance,” DiRuzzo says in the statement.

Trump says Peterson ‘choked’

Peterson’s response has been the focus of sharp criticism from officials, and the Florida Department of Law Enforcement is reviewing the law enforcement response to the shooting, the agency said.

President Donald Trump said last Friday that Peterson did a “poor job” and suggested he was a “coward” in how he responded to the shooting.

He further criticized Peterson on Monday, saying he “choked.” And Trump slammed other deputies.

“They weren’t exactly Medal of Honor winners,” Trump said. “The way they performed was frankly disgusting.”

Trump went even further, saying if he were at the school without a gun, he would have acted.

“I really believe I’d run in there even if I didn’t have a weapon and I think most of the people in this room would have done that, too,” Trump said. “But the way they performed was really a disgrace.”

Peterson was twice nominated as the School Resource Deputy of the Year and won the award in 2014, according to personnel records obtained by CNN. In 2015, Sheriff Israel personally praised Peterson and his 30-year tenure.

“Your dedication and allegiance are the best illustrations of the service [the sheriff’s office] provides to the people of Broward County,” Israel wrote.

CNN’s Sara Ganim, Chuck Johnston and Noah Gray contributed to this report.