The FBI this week detailed to Congress a series of mistakes and missed opportunities to intervene before a gunman killed 17 people at Marjory Stoneman Douglas High School in Florida -- including a revelation that staffers knew two warnings about suspect Nikolas Cruz were related, but still closed the case.

FBI Deputy Director David Bowdich made the comments in a closed briefing Tuesday with members of the House Judiciary and Oversight Committees.

In a summary released Wednesday to Fox News, Bowdich cited two tips that the FBI received about Cruz in September 2017 and January 2018 that were mishandled.

The 2017 tip alerted the FBI to a threatening YouTube comment, made by user Nikolas Cruz, which stated: “I’m going to be a professional school shooter.”

According to the summary, a FBI call taker “did not ask any standard investigative probing questions” about the 2018 tip.

The 2018 call taker was able to connect Cruz to the earlier call about the YouTube comment, but after discussing it with a supervisor, they decided not to pursue the matter and the case was closed.

House Judiciary Committee Chairman Bob Goodlatte, R-Va., and House Oversight and Government Reform Committee Chairman Trey Gowdy, R-S.C., said that “despite multiple opportunities, the FBI did not share information with state and local authorities” about Nikolas Cruz.

The FBI is reviewing its handling of the case and will report findings to Congress.

Cruz was charged Wednesday formally with 17 counts each of premeditated murder and attempted murder. The Broward County grand jury announced the 34-count indictment for Cruz, who police say opened fire inside the high school in Parkland, killing 17 people. The attempted murder charges were for the 17 other people injured in the mass shooting on Valentine’s Day.

Fox News' Catherine Herridge and The Associated Press contributed to this report.