Florida to investigate police response to school shooting that killed 17

— -- Florida is launching an investigation of the law enforcement response to the Valentine's Day mass shooting at Marjory Stoneman Douglas High School that killed 17 students and staff, the Governor's Office said Sunday.

The probe comes at the request of Gov. Rick Scott after the Broward County sheriff said video shows at least one deputy taking up a defensive position outside the building at the Parkland, Florida, school where the massacre occurred, but never going in to engage the gunman.

Scott's announcement was made shortly after the governor met with Rick Swearingen, commissioner of the Florida Department of Law Enforcement. It also came on the same day Republican lawmakers wrote the governor a letter asking him to suspend Broward County Sheriff Scott Israel, a Democrat, alleging, "incompetence and neglect of duty."

Swearingen's agency said it will "immediately" begin the investigation at the governor's request.

Sheriff Israel released a statement this afternoon saying his department "welcomes" the investigation and will "fully cooperate."

"This independent outside review will ensure public confidence in the findings," Israel said in the statement.

For the first time since the Feb. 14 massacre, thousands of Stoneman Douglas students and their parents were allowed back on the campus Sunday for an orientation with teachers, administrators and social service counselors. Classes at the school are scheduled to resume Wednesday.

Israel told ABC News last week that his office has already launched an internal investigation into reports that, besides the deputy seen on video, at least three other Broward County sheriff's deputies remained outside the school building during the rampage rather than entering the school.

Coral Springs Police Department officers were reportedly shocked to arrive at the shooting scene and see the Broward deputies still outside, with their pistols drawn and behind their vehicles, the South Florida Sun-Sentinel reported, citing an unnamed source from the Coral Springs Police Department.

Israel told ABC News Coral Springs Police Chief Anthony Pustizzi also contacted his office to report the response from Broward County deputies.

"If there is no wrongdoing on the part of our deputies, we'll move on," Israel said Friday. "If there is wrongdoing on the part of our deputies, we'll handle it accordingly as I have for five years as sheriff."

He announced at a news conference Thursday his decision to suspend Deputy Scot Peterson, the armed resource officer at the school, after reviewing video from the shooting and taking statements from witnesses and Peterson himself, Israel said.

He said the footage showed Peterson was armed and in uniform on campus during the shooting. He said Peterson should have gone in to “address the killer, kill the killer.”

Peterson, who met requirements for retirement, opted to resign after he was told he was being suspended, Israel said.

State Rep. Richard Corcoran, speaker of the Florida House of Representatives, penned a letter to Gov. Scott citing the "failures of Sheriff Israel and his deputies during and after the horrific shooting" at the high school.

In the letter, signed by Corcoran and 73 of his Republican colleagues, also wrote that it was "unacceptable and unforgivable" that Israel and his deputies failed to dig deeper into numerous complaints about the alleged gunman, 19-year-old Nikolas Cruz, long before the shooting at Stoneman Douglas.

Israel, who was elected sheriff as a Democrat in 2012 and won reelection in 2016, said last week his deputies received at least 23 calls for service regarding Cruz or his family between 2008 and 2017, including reports that he planned to "shoot up the school."

"In the years leading up to this unspeakable tragedy, Sheriff Israel, his deputies and staff ignored repeated warning signs about the violent, erratic, threatening, and antisocial behavior of Nikolas Jacob Cruz," Corcoran's letter reads.