It's unclear what they were arguing about but in the end one neighbor was dead and the other is in jail on $3 million bail.
Victor Paniagua, a 27-year-old known gang member, pleaded innocent Tuesday to first-degree murder and assault, as well as illegal gun possession.
He's accused of killing Abel Yanez Contreras, 47, in his own home on 22nd Avenue on June 3.
The two men were arguing in Contreras' bedroom when Contreras told Paniagua he didn't need his help, according to a witness. Another person said the men were insulting each other's mothers.
Paniagua allegedly pulling a handgun and pointed it at Contreras' head, then shot him in the chest, witnesses told investigators.
At some point, Contreras also was shot in the head.
As he was dying near the front door, a handyman who was at the house to fix the floors, went to help Contreras.
That's when Paniagua allegedly turned the gun on Efren Bueno-Gonzalez and said, "And you," in Spanish. The worker backed off and ran out.
After the shooting, Paniagua ran to his brother-in-law's home nearby and asked for a ride. Police later found him at the Tahitian Motel in Pasco.
Paniagua's trial is set for Aug. 6.