One year after the Federal Bureau of Investigation launched a probe into the Pulse nightclub attack, the agency continues to seek answers about gunman Omar Mateen and his actions leading up to the deadliest shooting in modern U.S. history.
"The FBI is grateful for the heroic work of the first responders and for the teams of doctors and nurses who worked tirelessly that night to save lives," FBI spokeswoman Andrea Aprea said.
The FBI declined to comment on the Pulse investigation, citing Department of Justice policy and the pending trial of Mateen's wife, Noor Salman, which is scheduled to begin in March 2018.
Salman is currently locked up in an undisclosed Central Florida jail on federal charges of obstruction of justice and aiding a terrorist organization. She has pleaded not guilty.
The FBI has not indicated when it will close its investigation into the Pulse attack.
As with all other officer-involved shootings, the Orlando Police Department launched an internal investigation into 11 police officers who took part in a gun battle with Mateen.
Officers fatally shot the gunman after breaching the back wall of the nightclub with explosives and an armored vehicle.
Although those officers have returned to regular duty, OPD's review of their actions will remain open until the FBI completes its investigation, a spokeswoman for the department said.
The Florida Department of Law Enforcement also conducted an investigation into the June 12, 2016 attack. That state agency completed its work about two months later.
The FDLE turned over its investigative report to the Orange-Osceola State Attorney's Office, which will determine whether police officers used the proper level of force under Florida law.
However, the State Attorney's Office will not begin to review the officers' actions until it receives the FBI's final investigative report, according to a spokeswoman.
The City of Orlando, Orange County government and the Orange County Sheriff's Office have no open investigations or internal reviews associated with the Pulse attack, according to representatives with those agencies.