While discussions of law enforcement's lack of follow-through on warnings ahead of this week's massacre at a Florida high-school have been active, The FBI has issued a statement admitting their error...

FBI Statement on the Shooting in Parkland, Florida

"On January 5, 2018, a person close to Nikolas Cruz contacted the FBI's Public Access Line (PAL) tipline to report concerns about him. 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.

Under established protocols, the information provided by the caller should have been assessed as a potential threat to life. The information then should have been forwarded to the FBI Miami Field Office, where appropriate investigative steps would have been taken.

We have determined that these protocols were not followed for the information received by the PAL on January 5. The information was not provided to the Miami Field Office, and no further investigation was conducted at that time."

FBI Director Christopher Wray said:

"We are still investigating the facts. I am committed to getting to the bottom of what happened in this particular matter, as well as reviewing our processes for responding to information that we receive from the public. It's up to all Americans to be vigilant, and when members of the public contact us with concerns, we must act properly and quickly.

"We have spoken with victims and families, and deeply regret the additional pain this causes all those affected by this horrific tragedy. All of the men and women of the FBI are dedicated to keeping the American people safe, and are relentlessly committed to improving all that we do and how we do it."

As a reminder, this is not the first time that protocols have not been followed, or when the FBI 'missed' a mass-shooter. As The Daily Caller's Peter Hasson notes, revelations that the FBI had been warned about Florida high school shooter Nikolaus Cruz fit an all-too-familiar pattern, in which apparent law enforcement errors have preceded mass murders.

The FBI was warned about Cruz after he posted on YouTube saying he was going to become a “professional school shooter.” The agency said they couldn’t identify the user who made the threat, despite Cruz posting under his own name. Five months later, Cruz pulled the fire alarm at Marjory Stoneman Douglas High School and began shooting his former classmates with his AR-15.

Other mass shooters and terrorists were similarly on the FBI’s radar — or should have been — before they carried out their deadly attacks.

Dylann Roof, who in 2015 shot nine people at a black church in Charleston, was allowed to purchase his weapon in part because of errors by FBI agents during the background check process, the agency said.

Pulse shooter Omar Mateen, who pledged allegiance to ISIS before killing 49 people at the Orlando nightclub, similarly seemed to have fallen through the cracks. The FBI investigated Mateen twice before the slaughter but ruled him not a threat both times.

The FBI knew that Fort Hood shooter Army Maj. Nidal Hasan had been in contact with al Qaeda terrorist Anwar al-Awlaki, but declined to investigate him. A congressional probe found that the FBI had failed to alert the Army about Hasan, and that the shooting could and should have been prevented. Hasan killed 13 people and wounded dozens of others in the 2009 shooting.

The FBI similarly missed opportunities to stop Tamerlan Tsarnaev, one of the brothers behind the 2013 Boston Bombing, a government review found. Russia warned the United States that Tsarnaev had associations with Islamic terrorists, leading an FBI-led task force to question the future terrorist. The agent who interviewed Tsarnaev closed the probe “having found no link or ‘nexus’ to terrorism.”

The task force was alerted a year later that Tsarnaev was leaving the country for Dagestan but declined to interview him or stop him from leaving the country. FBI agents later said the failure to interview Tsarnaev was a “huge” error, according to Boston Magazine.

Another school shooter who was on the FBI’s radar killed two students at a New Mexico high school just two months ago. Although the killing doesn’t meet the government’s definition of a mass shooting, the shooter was known to the FBI. The agency investigated the shooter, 21-year-old William Atchison, in 2016 after he commented online about committing a mass shooting.

We await Trump's response to his apparently fallible FBI's poor performance.