On Monday, the capital murder trial began in a Dallas courtroom for a man charged with killing his neighbors after a prolonged dog-poop dispute. Issues of race, language, economics and age complicate the already unusual case.

Chung Kim, 76, allegedly shot and killed Michelle Jackson and Jaime Stafford last February at Sable Ridge Condominiums in North Dallas. Jackson and Stafford, who are African-Americans in their 30s, lived in the unit above Kim and his wife. Kim, a South Korean immigrant, is using an interpreter for the trial and has previously stated he acted in self-defense.

It is well-documented that Jackson and Stafford frequently washed dog feces from their balcony onto Kim’s. The condo’s homeowners association received reports of dog-poop dumping dating back to August 2012.

“It’s not the way neighbors are supposed to act … but is taking a Glock 45 and shooting people in the head a reasonable way to resolve a dispute?”

Kim provided photos of his balcony’s poop-streaked windows, floors and walls to a variety of entities. Animal control eventually took the couple’s dog away, but the poop problems didn’t end. In December 2012, after Jackson gave birth to her fifth child, the couple began tossing dirty diapers over their balcony and onto the unit below them.

Kim and his wife owned their first floor condo and had lived there for more than a decade. Jackson was renting her unit through Section 8 housing on a month-to-month lease. In addition to voicing his complaints with the condo association, Kim reported the excrement issues to the Dallas Police Department, the City of Dallas Health and Human Services Department.

Condo maintenance supervisor Keith Morris said he was aware of the ongoing dispute between Kim and his neighbors. Morris said he had personally cleaned Kim’s balcony on at least two occasions, and once used a power washer to remove the poop.

Morris testified that he was picking up trash in the parking lot on Feb. 4, 2013, when he heard Kim yelling, followed by two gunshots. Then, he saw Jackson’s body lying on the floor of her second-story balcony.

Assistant district attorney Herschel Woods asked Morris who fired the gun.

“I was in shock,” Morris said. “It was Mr. Kim.”

Morris testified that he took cover behind the building because he feared for his life. When he emerged, Morris said he saw Kim step over Jackson’s lifeless body on the balcony and enter her unit while firing his weapon.

Jackson’s boyfriend, Jaime Stafford, was shot and killed as he tried to flee his residence.

At the time of the murders, a grainy security video from the condo’s parking lot and pool area shows a shadowy figure appearing to move from Kim’s ground-floor unit to the one directly above him occupied by Jackson and Stafford. Jurors craned their necks and squinted to make out the video, which also shows a figure enter Kim’s black Lexus SUV minutes after the murders and drive away from the complex.

Forensic scientist David Walker Spence testified that Kim had significant gun-shot particles on his hands when tested the day of the murders.

“There’s no way of me knowing, based on this testing, if one individual fired a gun or was just in proximity to the gun,” Spence said.

Police recovered a black Glock 45 handgun from Kim’s SUV the day of the murder. It was loaded and placed underneath the driver’s seat. 45-caliber shells and casings were found at the scene of the crime.

Carlata Robinson, the condo’s HOA president, testified about the extent of the animal and baby feces on Kim’s property. She said the amount, location and frequency of the feces made it a health issue.

On Jan. 31, 2013, more poop appeared on Kim’s balcony. This time, instead of being washed down from the balcony, it appeared to be piled up deliberately on Kim’s property.

“This issue has been ongoing for months,” Robinson wrote in an email the same day to the HOA board about Jackson and Stafford’s behavior. “Mr. Kim is about to reach his breaking point.”

Robinson had helped coordinate the couple’s eviction process, which was to begin Feb. 1. Robinson testified that she never told Kim about the pending eviction. Three days later, Jackson and Stafford were dead.

“This is terrible tenant behavior,” Woods said. “It’s not the way neighbors are supposed to act … but is taking a Glock 45 and shooting people in the head a reasonable way to resolve a dispute?” he asked.

“No,” Robinson said.