An Oklahoma City man allegedly killed his girlfriend and locked himself in the house with her decomposing body for "several days," police said. 

A passerby called police Saturday morning after possibly seeing a dead body in the garage of northwest Oklahoma City home, police said.

The suspect, 31-year-old Jake Harris, ignored responding officers' orders to surrender and barricaded himself inside, police said. 

The SWAT team rolled through the small, U-shaped road of Altadena Avenue, and was locked in an hours-long standoff until Harris allegedly began "shooting the shotgun randomly inside his residence," according to the probable cause affidavit.  

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jake harris mugshot

Jake Harris, 31, allegedly killed his girlfriend in his Oklahoma City home and stayed with her body for "several days," according to police. (Oklahoma Detention Center)

The SWAT team used a battering ram to blast through the door and fired nonlethal rounds at Harris before slapping the cuffs on him, according to police.

Officers found Amanda Miller's body in the garage, and Oklahoma City police said they believe Harris allegedly shot the 40-year-old woman "several days" earlier.

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Harris allegedly told police that the couple had an argument three days before the police standoff – March 22 – and grabbed the shotgun, the affidavit says.

Miller "grabbed the barrel and the gun went off," Harris allegedly told arresting officers, according to the affidavit. 

oklahoma city crime scene

The home at 4212 Altadena Ave., Oklahoma City, center, was where Jake Harris allegedly killed his girlfriend, Amanda Miller. (Google Street View)

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Because she was dead, he told police he didn't call an ambulance and kept her in the bedroom and then moved her to the garage on the second day, the affidavit alleges. 

After moving the body, Harris allegedly tried to clean the crime scene. 

Miller leaves behind four daughters and 10 grandchildren. 

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One of Miller's daughters, Haven Montoya, expressed her grief on Facebook.

"No, I'm not okay," she wrote in one post. "I was a mama's girl. That was my best friend. Ima make it to her too. I love you mommy." 

Harris was charged with first-degree murder and is being held in the Oklahoma County Detention Center without bond.