FBI tipped off about Florida gunman's 'desire to kill people' last month -- but failed to investigate
Nikolas Cruz, seen here in a booking photo obtained February 15, 2018 courtesy of the Broward County Sheriff's Office, has been charged with premeditated murder in the shooting deaths of 17 people at a Florida high school. (Broward County Sheriff's Office/AFP / Handout)

The FBI was tipped off about accused Florida gunman Nikolas Cruz last month but apparently failed to follow up on the information.

A person close to the accused killer called the FBI's public tip line Jan. 5 to report "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 tip should have been forwarded to the bureau's Miami office but was not, and no further investigation was conducted.

“These protocols were not followed,” FBI said in a statement.

That failure is now the subject of an internal investigation.

The 19-year-old Cruz has been charged in the deaths of 17 students and teachers Wednesday at Marjory Stoneman Douglas High School in Parkland.

A Mississippi man reported to the FBI disturbing comments about school shootings left by a YouTube commenter named Nikolas Cruz in September, but agents were unable to locate and identity the internet user who made them.