The FBI failed to follow its protocols on a tip that Nikolas Cruz, who is suspected of opening fire at a high school, might carry out a school shooting.

In early January, a little over a month before a massacre at Marjory Stoneman Douglas High School killed 17 people, a person close to Mr Cruz contacted the bureau’s public tip line to report he could be a danger. But that information was never forwarded to the FBI’s Miami field office.

“I am committed to getting to the bottom of what happened in this particular matter, as well as reviewing our processes for respond to information we receive from the public”, FBI director Christopher Wray said in a statement.

The call included “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 FBI said in a statement.

As more information emerges about Mr Cruz, law enforcement officials are facing intensifying questions about whether they missed warning signs.

The FBI acknowledged that it had received a separate tip about an online commenter under the moniker 'nikolas cruz' saying “Im going to be a professional school shooter”.

Florida shooting – in pictures Show all 10 1 /10 Florida shooting – in pictures Florida shooting – in pictures Police arrest a suspect in connection with the shooting at the Marjory Stoneman Douglas High School in Parkland, Florida Reuters Florida shooting – in pictures Parents wait for news after reports of a shooting at Marjory Stoneman Douglas High School in Parkland, Florida AP Florida shooting – in pictures Anxious family members wait for news of students AP Photo/Wilfredo Lee Florida shooting – in pictures Students being evacuated from the school AP Florida shooting – in pictures Students being evacuated from the school Getty Florida shooting – in pictures People gather waiting for word from students AP Florida shooting – in pictures Parents waiting for news on their children AP Florida shooting – in pictures People gather at a hotel where students were taken after the shooting Getty Florida shooting – in pictures Florida Governor Rick Scott speaks to the media as he visits Marjory Stoneman Douglas High School following the shooting AFP/Getty Florida shooting – in pictures Dr. Igor Nichiporenko, Medical Director Trauma, left, and Dr. Evan Boyer, Medical Director, Emergency Services, speak about treating victims and the suspect at a press conference outside Broward Health North hospital AP

Attorney General Jeff Sessions said in a statement that “we must do better,” saying he had directed a review of the response process at the FBI and the Justice Department.

“We will make this a top priority,” Mr Sessions said. “It has never been more important to encourage every person in every community to spot the warning signs and alert law enforcement”.

Mr Cruz has been charged with 17 counts of premeditated murder. He has not yet entered a plea, but an arrest affidavit alleges that he admitted to being “the gunman who entered the school campus armed with a AR-15 and began shooting students that he saw on the hallways and on the school grounds”.