The male officer was responding to a domestic incident in Tacoma, Washington, when he was shot. Authorities have confirmed he died after being taken to Tacoma General Hospital.
The first gunshots were heard at around 5.15pm (00.15 GMT) local time and were followed by a series of further shots at around 7.30pm.
Police were able to get adults and children out of the house near East E Street and East 52nd Street following the shooting but the suspect has barricaded himself inside the house.
Kristi Croskey was in the house when the shooting took place but authorities were able to get her out of the property before anyone else was shot.
She had been a previous resident in the house but moved out of the property seven months ago and returned to collect some possessions.
She said: “I’m caught off guard just like everybody else.”
Dozens of police officers have lined the street outside Tacoma General Hospital after the officer was pronounced dead.
The shooting of the unnamed policeman now brings the number of police officers killed on duty in the US this year up to at least 62.
A police spokeswoman confirmed this is the first Tacoma Police officer killed by gunfire since 1997.