The two-page report by Chief McNally, which outlines his interactions with the authorities outside the school, was the latest account of frustration and bewilderment over the law enforcement response.

After he arrived at the school, he offered four times to send in paramedics while the police were watching security footage to find the gunman, identified as Nikolas Cruz, a former student. The deputy chief told Captain Jordan that the teams — which each consist of three to four police officers and at least three paramedics — were specially trained to treat victims in an active shooter situation and would enter only the areas that the police had searched.

He offered two more times after the police discovered the video delay and saw that the gunman had escaped unnoticed from the building. The deputy chief was told to wait. “Once again, the incident commander advised, ‘She would have to check and let me know,’” he wrote in the report.

A Broward County Sheriff’s Office spokeswoman said on Friday that paramedics were allowed in only “after it has been confirmed the threat is mitigated.”

“Reporters will be able to provide a more accurate narrative once all the facts are gathered and the investigation is completed as well as the findings from the independent reviews by the Florida Department of Law Enforcement and the M.S.D. Commission,” the spokeswoman said, referring to the Marjory Stoneman Douglas Commission.

The gunman opened fire with a semiautomatic AR-15, a civilian version of the military’s standard rifle that produces devastating wounds to organs and severe bleeding. Many victims bled to death before reaching the hospital.