When police officers arrived on the scene of the shooting of Trayvon Martin on the rainy night of Feb. 26, they tried frantically to revive the 17-year-old, who had been shot in the chest and was lying motionless behind a row of town houses in a gated community in Sanford, Fla.

Officers administered CPR and “rescue breaths,” and one officer said in a report that he “put gloves on, placed a plastic bag over the wound to the victim’s chest and proceeded to provide chest compression.” He added, “Our efforts were continued until” the Sanford Fire Department “arrived and took over.”

“Briefly thereafter, SFD declared the victim deceased,” the officer’s report said.

These and other details were part of a trove of new documents and photographs released Thursday by the special prosecutor in the case, Angela B. Corey, that form part of the discovery process in the murder case of Mr. Martin. Ms. Corey was appointed by Gov. Rick Scott to handle the case, which has galvanized national attention.

George Zimmerman, 28, the neighborhood watch volunteer charged last month with second-degree murder in the case, was apparently known to some members of the Sanford police, according to the documents. He had called the police frequently and had contacted them to set up the neighborhood watch in the Retreat at Twin Lakes, where he lived and where he shot Mr. Martin.