Police officer who fatally shot Kansas man in swatting case won't be charged: DA Andrew Finch was killed in a mixup after a prank call last December.

The Kansas police officer who shot and killed a man on his front porch last December following a prank call will not be charged, the county's district attorney announced Thursday.

Andrew Finch was killed after police responded to a 911 call that alleged someone at his Wichita, Kansas, address had shot his father and was holding his remaining family hostage with a gun. When police responded, Finch answered the knock on his door and stepped into the doorway, according to police. Finch initially complied with an order to raise his hands, according to the police account, but then lowered his hands and reached for his waistband.

An officer opened fire and Finch was killed, according to police.

"The officer believed Mr. Finch was the suspect who had shot his own father and had been holding his younger brother and mother hostage," Sedgwick County District Attorney Marc Bennett said Thursday. "This officer perceived these movements by Mr. Finch and believed the subject that he was looking at, Mr. Finch, was reaching for the gun that he would have used to shoot his father moments earlier. The officer believed he saw a gun come up in Mr. Finch's hands. The officer stated that he discharged his weapon, thinking that Mr. Finch presented an imminent risk to the officers."

The Finch family expressed disappointment in the decision not to press charges through their attorney, Andrew Stroth.

"The family is devastated and disappointed by the District Attorney’s decision," Stroth said in a statement. "Andy Finch was unjustifiably and unconstitutionally executed in the sanctity of his own home."

The case brought national attention to the phenomenon of "swatting," a prank common in online gaming where a person makes up an address and crime in order to get police, i.e., SWAT teams, to show up at the address.

Tyler Barriss, 25, of Los Angeles, has been charged with involuntary manslaughter, giving a false alarm and interference with a law enforcement officer for allegedly making the 911 call which resulted in Wichita police arriving at Finch's doorstep.

"This shooting should not have happened," Bennett said. "But this officer's decision was made in the context of the false call."

Barris, who has been linked to other swatting incidents, told Los Angeles ABC station KABC in January during a jailhouse interview that he regretted that the hoax led to Finch's death. Barriss had made at least 20 other prank calls about crimes prior to the deadly swatting incident, including a bomb threat to KABC's studios in 2015, the Glendale Police Department said.

"I never intended for anyone to get shot and killed," he told the station. "I just wish I could have rewound somehow and just never done it."

Finch's family had called for both Barriss and the officer to be punished for the shooting.

"The family wants that young man held criminally responsible, but let’s be very clear about what happened," Stroth told ABC News in January. "The swatter didn’t shoot the bullet that killed Andy Finch. Responsibility for that case resides in that officer that used his high-powered rifle to shoot and kill Andy."

Finch, 28, was the father of two young children.

The Wichita Police Department released a lengthy statement following the decision not to charge its officer, saying the incident "has weighed on the hearts of the WPD and community" and the department continues to "extend sympathy to the Finch family and the officers involved." The department also outlined steps it will now take, including an internal investigation and a review of training and policies.

The Finch family filed a lawsuit in January against the city and 10 police officers with the Wichita Police Department.

ABC News' Jim Vojtech contributed to this report.