Pittsburgh Police were called to a domestic disturbance that became a standoff Sunday night in Knoxville.
The incident was reported around 6 p.m. in the 100 block of Bausman Street.
When officers arrived, they were met by two women who said they were assaulted during a dispute another woman who had a gun.
SWAT officers were called in after she barricaded on the second floor of the house.
Four hours later she was taken into custody.
Charges are pending.