Broward County Sheriff Scott Israel said Sunday he should bear no responsibility for the missed warning signs before the Feb. 14 mass shooting at Marjory Stoneman Douglas High School that left 17 students and faculty dead.

“I can only take responsibility for what I knew about,” Israel said in an interview on CNN’s “State of the Union.” “I’ve given amazing leadership to this agency.”

Israel has faced intensifying questions about the agency’s response to the massacre since the revelation that an armed deputy on the scene did not enter the school while the gunman was inside.

That deputy, Scot Peterson, retired last week after being suspended.

Israel said Sunday he should not be faulted for Peterson’s actions. “You don’t measure a person’s leadership by a deputy not going in,” he said.

State. Rep. Bill Hager, R-Boca Raton, sent a letter to Gov. Rick Scott on Saturday attacking Israel for “neglect and incompetence” and calling for his removal.

Israel said Sunday, “Of course I won’t resign” and said the letter was “shameful” and “politically motivated.”

National Rifle Association spokeswoman Dana Loesch, speaking Sunday on ABC’s “This Week,” also accused the sheriff’s office of “dereliction of duty” and said Israel should face increased scrutiny.

“I wish that as much attention were given to the Broward County sheriff and their abdication of duty as trying to blame 5 million innocent law-abiding gun owners all across the country for this,” Loesch said. “I want to see as much attention on the Broward County sheriff, the FBI, the two FBI tips and the numerous calls. … Families and neighbors called the Broward County sheriff’s office to report this individual, and they did not follow up.”

David Hogg, a senior at the school, called Israel “a good man” during an interview on ABC’s “This Week” and said “he cares about the people.” But Hogg said there were breakdowns in procedures. “Were there mistakes made? Absolutely.”

More than a dozen calls were made to authorities with warnings about the accused gunman, 19-year-old Nikolas Cruz, before the attack. Israel said Sunday that most of them were handled appropriately but that in two of the calls “we’re not sure if deputies did everything they could have or should have.”

Israel said an internal investigation into the agency’s handling of the shooting is ongoing. “We will investigate every action of our deputies, of our supervisors,” he said, “and if they did things wrong I’ll take care of business in a disciplinary matter, just like I did with Peterson.”

During a rampage inside the Parkland high school, police say, Cruz fatally shot 17 students and faculty before blending in with the fleeing teenagers and escaping the campus. He was taken into custody later that afternoon. He now could face a potential death sentence.

Police from the neighboring city of Coral Springs have said three other Broward deputies besides Peterson were waiting behind cars outside the school when they responded to the shooting. Israel said Sunday that only Peterson, then the school resource officer, was at the school during the shooting.