The FedEx shooting "probably only lasted one to two minutes,” the deputy chief of criminal investigations for Indianapolis police told CNN early Friday morning.
"It was very short," Craig McCartt said, adding that the suspect exited his vehicle and immediately began shooting while in the parking lot.
According to McCartt, the suspect entered the facility and continued shooting.
Police officers then arrived at the scene.
McCartt said he believed the suspect encountered police officers inside the facility and then took his own life.
Officers found eight deceased people both inside the building and in the parking lot.
McCartt said officers were still working to confirm the identity of both the victims and the shooter. Officers and FedEx are working to reunite employees with their families.
He said a policy where FedEx employees do not carry cell phones while working had complicated the reunification effort.
Watch the full interview: