CNN  — 

As more details emerge about the Florida high school massacre that left 17 people dead, some of the first officers who rushed to the scene are sharing their accounts of the moment they arrived.

“I just want to, you know, get it off my chest in case something does happen,” the woman said, according to a transcript of the January 5 call reviewed by CNN.

Nearly six weeks after that call, Cruz gunned down 17 people at his former high school in Florida – one of the deadliest mass shootings in modern US history.

In the weeks leading up to the February 14 massacre, people reported warning signs about Cruz, 19, but law enforcement officials failed to act. And during the shooting, the deputy assigned to the school stayed outside the building where the carnage happened, authorities said.

Here are other revelations that emerged this week:

Tipster warned the FBI

An unidentified woman close to Cruz called the FBI tip line to describe a young man with an arsenal of knives and guns who was “going to explode.” She said she feared him “getting into a school and just shooting the place up.”

“I just want to, you know, get it off my chest in case something does happen and I do believe something’s going to happen,” the woman said, according to the transcript CNN reviewed.

The woman said Cruz had the mental capacity of a 12- to 14-year-old and had been kicked out of school for throwing chairs at students and teachers. She also provided the FBI with the user names for at least three of Cruz’s Instagram accounts, where he wrote that “he wants to kill people” and posted photos of mutilated animals.

The FBI admitted last week it had failed to act on that tip.

school shooting tipster's call to FBI 1
Tipster warned FBI of Parkland school shooter
03:31 - Source: CNN

Separately, the FBI was warned in September about a YouTube commenter named Nikolas Cruz, who wrote: “Im going to be a professional school shooter.”

Sources: While bullets flew, deputies waited

When Coral Springs police officers arrived at the school, they were surprised to find that the school resource officer and three sheriff’s deputies had not entered the building, sources tell CNN.

With direction from the Broward deputies who were outside, Coral Springs police soon entered the building. New Broward County sheriff’s deputies arrived on the scene, and two of those deputies and an officer from Sunrise joined the Coral Springs police as they went into the building.

It’s unclear whether the shooter was still in the building when they arrived.

The sources cautioned that surveillance tapes are under review and official accounts could ultimately differ from recollections of officers on the scene.

PARKLAND, FL - FEBRUARY 14:  People are brought out of the Marjory Stoneman Douglas High School after a shooting at the school that reportedly killed and injured multiple people on February 14, 2018 in Parkland, Florida. Numerous law enforcement officials continue to investigate the scene.  (Photo by Joe Raedle/Getty Images)
Sources: 4 armed deputies didn't enter school
03:24 - Source: CNN

Peterson resigned following his suspension Thursday, and an internal investigation is pending.

The Broward County Sheriff’s Office said it is investigating reports that the three additional deputies didn’t attempt to enter the building as the shooting was going on.

Bill Hager, a Florida state representative, called on Gov. Rick Scott to remove Broward County Sheriff Scott Israel from his post “for neglect of duty and incompetence.”

“An investigation into the incomprehensible inaction of these deputies by Sheriff Israel will do nothing to bring back the 17 victims. The Sheriff was or should have been aware of the threat Cruz presented to his community and chose to ignore it,” Hager said in a letter to the governor.

“Sadly, he was not the only one that ignored it. DCF, Broward County Schools, the FBI and the BSO all had pivotal information but failed to act appropriately and failed to communicate appropriately. This failure to communicate shows that a modernization of our law enforcement and state government agencies is necessary,” he added.

In a letter of response to the governor, Israel said he was proud of the work that many of his deputies and other agencies did the day of the shooting and that he was appalled by Hager’s “need to engage in disingenuous political grandstanding, perhaps in the hope he will garner some headlines, at the expense of the truth.”

In 911 call, a teen in crisis

Weeks after Cruz’s mother died in November, he reportedly called 911 to describe a tumultuous encounter with a family that had recently taken him in.

In a call obtained by CNN affiliate WPTV, the caller, identified by the West Palm Beach station as Cruz, talks about a blowup. The man, whose voice is unsteady, says he doesn’t know where he is calling from because he is new to the area.

The call was placed shortly after Cruz and his younger brother moved in with the Deschamps family in Palm Beach County.

On November 28, Rocxanne Deschamps, who took them in, called 911 saying that Cruz was distraught and violent after losing a photo of his mother, according to the Palm Beach County deputy’s report and dispatcher notes. She told authorities that Cruz was confronted by her son, Rock, and ran from the home, saying he “was going to get his gun and come back,” records show.

Cruz placed a 911 call after he left, WPTV reported.

“The thing is, I lost my mother a couple days ago, so, like, I’m dealing with a bunch of things right now,” Cruz said, according to the TV station.

Cruz lived with that family briefly, then moved out.

PARKLAND, FL - FEBRUARY 14:  People are brought out of the Marjory Stoneman Douglas High School after a shooting at the school that reportedly killed and injured multiple people on February 14, 2018 in Parkland, Florida. Numerous law enforcement officials continue to investigate the scene.  (Photo by Joe Raedle/Getty Images)
911 call: Cops warned Florida shooter had guns
00:57 - Source: CNN

More revelations

Years before Cruz targeted his former high school in Parkland, the sheriff’s office had received 23 calls related to him or his brother, Israel said.

Two deputies have been placed on restricted duty pending an internal investigation on how they addressed the warnings, Israel said.

In the 2016 one, officers received information from a neighbor’s son that Cruz planned to “shoot up” an unknown school. There was a picture of a “juvenile with guns” on Instagram, according to police records.

In that case, a deputy responded and determined Cruz had knives and a BB gun. The information was forwarded to a school resource officer, police records show.

In November’s incident, a caller warned that Cruz was collecting guns and knives and wanted to join the Army. The caller said Cruz was suicidal and could be a “school shooter in the making,” according to police records.

The report said that officers at the time did not write a report on the tip. Cruz was no longer living at the listed Parkland address and lived in Lake Worth, Florida, according to police records. The deputy referred the caller to the Palm Beach County Sheriff’s Office.

Both calls are listed as being under internal affairs investigation. The 21 other calls are listed as “no policy violation apparent.”

CNN also obtained records from the Palm Beach County Sheriff’s Office that detailed deputies’ interactions with Cruz in the home where he lived for a few weeks after his adoptive mother’s death last year.

Shooting footage not shown live

In yet another revelation, authorities said Thursday that surveillance footage from the school shooting was not shown live, as responding officers initially thought.

“The delay never put us in a situation where any kids’ lives were in danger, any teachers lives were in danger,” Pustizzi said at a news conference.

At some point, there was a miscommunication and officers believed they were watching real-time footage, he said.

“Somebody would say, ‘He’s on the second floor,’ and we had guys on the second floor saying, ‘We’re on the second floor, we don’t see him,’” Pustizzi told the Sun Sentinel.

That’s when officers figured out there was a tape delay.

CNN’s Rosa Flores, Chuck Johnston, Eric Fiegel, Darran Simon, Scott Glover and Dakin Andone contributed to this report.