(CNN) Before Nikolas Cruz killed 17 people at his former high school in Florida on February 14, law enforcement officials received several calls from people concerned about the young man's guns and violent behavior. In one, a caller said Cruz planned "to shoot up" an unnamed school.

Here are details about some of those calls:

January 5, 2018

Call made to: FBI

What the caller said: The FBI said the caller provided information about "Cruz's gun ownership, desire to kill people, erratic behavior, and disturbing social media posts, as well as the potential of him conducting a school shooting."

The response: The information should have been assessed as a "potential threat to life," but The information should have been assessed as a "potential threat to life," but the bureau did not appropriately follow established protocols in following up on the tip, the FBI said.

"The information was not provided to the Miami Field Office, and no further investigation was conducted at that time," the FBI said.

November 30, 2017

Call made to: Broward Sheriff's Office

What the caller said: A caller warned that A caller warned that Cruz was collecting guns and knives, and wanted to join the Army. The caller also said Cruz wanted to kill himself and could be a "school shooter in the making," according to police records.

The response: Cruz was no longer living at the Parkland address listed in the report -- he'd moved to Lake Worth, Florida, according to police records. The deputy referred the caller to the Palm Beach County Sheriff's Office. That case is now listed as under internal affairs investigation.

November 27, 2017

Call made to: Palm Beach County Sheriff's Office

What the caller said: The family with whom Cruz was living at the time called The family with whom Cruz was living at the time called the Palm Beach County Sheriff's Office four days after Thanksgiving when Cruz lashed out at them, according to the Palm Beach deputy's report and dispatcher notes. It was the second time in four days authorities had been called about the young man. The family warned the police dispatcher their 22-year-old son had had a disagreement with Cruz, and Cruz said "he was going to get his gun and come back," records show. The mother of the family said Cruz had "bought a gun from Dick's last week and is now going to pick it up."

The response: The deputy spoke to the two feuding young men, who "hugged and reconcile(d) their differences," the report said. Cruz also apologized for losing his temper.

November 24, 2017

Call made to: Palm Beach County Sheriff's Office

What the caller said: On the day after Thanksgiving, Cruz was at work at a Dollar Tree store. The son of the family he was staying with called 911 to report that an "adopted 19-year-old son" had possibly hidden a "gun in the backyard," according to a dispatcher's notes. Rock Deschamps told law enforcement no weapons were allowed in the household.

The response: It's unclear whether sheriff's deputies conducted a search. The incident was classified as "domestic unfounded," which means a deputy didn't find proof to back up the claim.

November 1, 2017

Call made to: Broward County Sheriff's Office

What the caller said: A relative reported that Cruz had rifles, and asked deputies to come and recover them.

The response: A deputy responded. A family friend agreed to take possession of the firearms, and deputies did not issue a report. After the high school shooting last week, deputies re-interviewed the same relative who made the call and she denied knowing about firearms. She said she only knew about BB guns, police documents show.

September 2017

Call made to: FBI

What the caller said: A YouTube video blogger warned the FBI about a possible school shooting threat. "Im going to be a professional school shooter," said a YouTube comment left by a user with the name Nikolas Cruz.

The response: The FBI's field office in Mississippi interviewed the blogger the next morning. He told the agents he didn't know anything about the user. After the February 14 school shooting, an FBI official said agents did investigate but were unable to further identify the commenter.

February 5, 2016

Call made to: Broward County Sheriff's Office

What the caller said: Officers received "third hand 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.

The response: 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. That case is listed as under internal affairs investigation