UPDATE: Sheriff: Bella Vista woman, 68, killed son, husband, daughter-in-law, dogs and self

A 68-year-old woman shot and killed her son, husband and daughter-in-law — as well as the family's three dogs — then set the family home on fire and shot herself earlier this month in Bella Vista, deputies said Thursday.

Sgt. Brian Jackson said Teresa Mae Wilson shot the three victims multiple times each on Jan. 7. They are her husband, 69-year-old Gary Lynn Wilson; son Ellis Leroy Wilson II, 44; and daughter-in-law Zoe Lynn (Burnett) Wilson, 20, who was married to Ellis Wilson. 

MORE:Bella Vista family killed in suspected murder-suicide identified

Interviews with surviving family members indicated there had been "long-term tension" at the home, Jackson said. But deputies are still piecing together exactly what may have made Teresa Wilson snap, he said.

"Due to the tension, it is believed Teresa may have reacted and committed the acts," he said in a news release. 

Jackson said the three homicide victims died from the gunshots before Teresa Wilson apparently set fire to the home they all shared at 11935 Bella Vista Court.

Deputies found a burnt .380-caliber semi-automatic gun "known to belong to Teresa" in her lap when they discovered her body, Jackson said.

Evidence also indicates the fire at the home was an arson set in a northwest room of the house, Jackson said, and signs of smoke inhalation found during Teresa May's autopsy indicated she was alive when it started. She died from a self-inflicted gunshot wound to the head, Jackson said her autopsy showed.

MORE:Man sentenced to prison in fatal 2015 wreck back in jail

Firefighters responded to the blaze about 5 p.m. Jan. 7, though Jackson didn't say when the shootings happened.

In addition to the three homicide victims, Teresa May apparently shot three dogs in the house, while two cats died from smoke inhalation, Jackson said. 

Wilson's daughter, Ronnia Krug, recently posted a tribute to her family members on Facebook, praising her mother in particular. 

"Missing my family," Krug wrote in her Monday Facebook post. "Loving them and wanting them to be remembered as the kind, caring parents as everyone knew them as."

Krug also wrote that Teresa Wilson used to work at Sears and helped raise her daughter's children. 

"She was my best friend for years," she wrote. "I would always talk to her about everything. She was a great listener. ... I don't know what I would have done without her."

Jackson said shell casings found at the scene were from the gun found on Teresa Wilson's lap, and "no evidence or information has been discovered that any other person (s) are responsible for the deaths and fire." 

Anyone with information on the case is asked to call the sheriff's major crimes unit at 530-245-6135, or email the unit at mcu@co.shasta.ca.us. 

MORE NEWS:

Murder defendant wants to plead guilty

Jail inmate accused of attempted murder injured in fall

Barking up the right trees? Sheriff says man repeatedly climbed trees to avoid arrest