ORLANDO, Fla. — An Orlando police sergeant is recovering after he was shot in the knee by his own gun while on duty.
Orlando police Chief John Mina has told officers who use the type of gun to have it checked before they use it again.
Questions remain about why the gun went off.
Police said they're conducting an internal investigation and that the Orange County Sheriff's Office is also investigating the incident.
Channel 9 isn't identifying the sergeant because he works undercover, but two sources said the veteran officer was responding to a SWAT call last month when he dropped one of his guns and it went off, injuring his knee.
Sources said the weapon was his personal gun, one he and other plainclothes officers are allowed to carry while on duty.
According to agency policy, "Officers may carry more than one weapon, but they must re-qualify with that weapon at each regularly-scheduled department range shoot."
Shortly after the incident, Mina sent a letter to officers, warning those who use a certain type of gun to have it tested.
"Members who are currently using the Sig Sauer P320, either on-duty or off-duty, in a law enforcement capacity, shall immediately have their firearm inspected by MPO Kevin Williams or MPO John Gilvin," the letter said. "The P320 is required to be upgraded by Sig Sauer. This firearm must have the upgrade, and then any member who is approved, must re-qualify after the upgrade and prior to carrying."
Sig Sauer said on its website that it has issued a voluntary upgrade on the P320 weapon.
"Recent events indicate that dropping the P320 beyond U.S. standards for safety may cause an unintentional discharge," a press release said.
The company said that, after receiving input from law enforcement officers and military members, it's offering safety enhancements.
The injured sergeant has been with Orlando Police Department since 1991. It's unclear how long it will be before he can return to work or if the injury will end his career.