GRAHAM, Wash. -- Pierce County prosecutors filed aggravated murder charges Tuesday against the man accused of killing two neighbors in Graham.

Daniel Thomas Tavares Jr., 41, is accused of killing Brian Mauck, 30, and his wife Beverly Mauck, 28, on Saturday. Investigators said the couple died of multiple gunshot wounds.

The charges carry the possibility of death penalty, which prosecutors in the case said they are considering.

Tavares pleaded not guilty to the charge.

Tavares’ wife, Jennifer Lynn Tavares, 37, was charged Tuesday with one count of rendering criminal assistance for lying to police about her husband’s whereabouts and driving with him to Point Defiance Park where they threw a gun off a cliff, court documents said.

According to probable cause documents, while under questioning, Daniel Tavares told investigators he had been hired to kill the couple because of a gambling debt. He then admitted that story was a lie.

Court documents said Tavares then told police he went to the Maucks’ home with his wife Jennifer to collect a $50 that was owed to him by Brian Mauck. While there, Tavares said that Brian insulted him and Mauck’s wife, Beverly, insulted his wife.

Documents said that Tavares then produced at .22-caliber revolver, grabbed a hand towel and covered the gun’s muzzle to muffle the sound of the shot. He then shot Mauck in the face. Tavares said that once Mauck fell to the floor, he shot him again in the back of the head.

Tavares said that Beverly Mauck witnessed her husband’s shooting and tried to escape out the front door. Tavares said he chased her, grabbed her by the hair and shot her in the back of the head, documents said.

Tavares told police he then dragged her body next to her husband’s and covered them up with a blanket because “he respected them.”

Police said that Tavares told them that after 20 years in prison he was not going to put up with being insulted.

Tavares’ father told KIRO that his son had served 17 years in prison for stabbing his mother to death in Massachusetts and was released from prison in June.

Tavares’ father, Daniel Tavares Sr., said he received several threatening letters from his son in prison.

“I got a call Friday afternoon from some girl with a Massachusetts accent that said ‘Hey this is to let you know Daniel is out and he’s on his way down there,’ and that’s when I went out and bought a gun,” Tavares Sr. said.

According to Tavares Sr., Tavares spent most of his time in disciplinary isolation where he served time at Massachusetts Correctional Institute at Walpole.

After his release, Tavares move to Washington to marry Jennifer Lynn Tavares, a woman who had been his prison pen pal.