Israel, the county’s first Jewish sheriff acknowledged on Sunday on CNN’s “State of the Union” with Jake Tapper that an armed Broward County Sherriff’s deputy did not enter Marjory Stoneman Douglas High School when former student Nikolas Cruz began firing an AR-15 rifle in the halls of the school.

Israel said when he saw video of the incident and realized that Deputy Scot Peterson did not perform his job, he called him in and suspended him without pay. He said his office was moving toward firing Peterson when he resigned.

Three other deputies are alleged to have arrived at the scene and not entered the building as well. This is currently under investigation, Israel said,

“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,” Israel told Tapper.

Tapper also brought up the at least 18 calls made to the Broward County Sheriff’s Office related to the shooter prior to the shooting. What action was taken following each call currently is under investigation.

Tapper asked Israel if he would resign, citing a letter from Florida State Representative Bill Hager to Florida Gov. Rick Scott, asking him to remove Israel for “negligence of duty and incompetence.”

“It was a shameful, politically motivated letter that had no facts,” Israel responded. “And of course I won’t resign.”