(CNN) A security officer was shot and killed by two suspected bank robbers in Gary, Indiana, Friday afternoon, authorities said.
According to the Lake County Sheriff's Office, the security officer was "ambushed" and killed outside the Midwest Bank by the suspects who were armed with a handgun and a rifle. Authorities believe the suspects then entered the bank and demanded money.
One of the two male suspects has been taken into custody, but the other is yet to be apprehended, according to a release from the Sheriff's Office.
Lake County Sheriff's Department officers were first on the scene and used K-9 units to track down the suspect. The FBI has now taken the lead on the investigation.
The security guard is not being identified by authorities.