Jordan Fricke was charged Sunday with first-degree intentional homicide, along with felony weapon and drug charges in the fatal shooting Wednesday.
According to the criminal complaint, Fricke told investigators he thought he heard the people hammering on his door yell "police" but he didn't think it was actually the police trying to break into his home.
While the door was being breached by police using a ram device, Fricke fired an AK-47 pistol four times through the opening the ram device created, striking Rittner in the chest.
A 26-year-old Milwaukee man has been charged in the killing of a Milwaukee police officer. Authorities arrested Fricke soon after the shooting. While Rittner was using the ram another officer yelled "Police!" and nearly immediately four gunshots are fired through the opening door from inside the apartment.
According to police, Fricke was being served a search warrant in regards for the illegal sale of drugs and guns.
The team then carried Officer Rittner down the stairs and outside into the yard where they tried life saving measures until paramedics arrived. The bullet entered Officer Rittner at the left upper chest/shoulder area and went through the left long, the aorta, the right lung and ended at the right shoulder and chestwall.
Fricke remained in jail Sunday.
Bond has been set at one-million dollars cash, and Fricke is expected to appear again in court February 14 for a preliminary hearing.
Rittner's funeral is scheduled for Wednesday at Oak Creek Assembly of God Church in Oak Creek, Wisconsin.