Alison Dupras knew her father was involved in the December 2018 killing of her mother and grandmother as soon as she heard the tragic news. Speaking to People, Alison said, “I know that my father did this, I knew that as soon as I knew what had happened. I knew it right away. Right then and there, I knew.” She even told Alan Dupras to turn himself in but in vain. “That’s all I wanted was for him to confess, either to me or to the authorities, and I just knew that wasn’t going to happen.”

During the months-long investigation into the incident, Alison was in regular contact with authorities and kept pushing for an arrest. She even held a protest late July at the district attorney's office.

“We are gathering silently and peacefully to let [the district attorney] know that we as a community cannot accept anything other than an arrest and full trial...I have been told the detectives are certain of who has committed this atrocity and any jury would find the suspect guilty," she said, The Fresno Bee reports.

Authorities confronted the 58-year-old suspect nine months after the double homicide which claimed the lives of Alison's mother, 55-year-old Jennifer Dupras, a retired elementary school principal, and her 88-year-old grandmother, Cynthia Houk. Alan is now facing charges of murder as well as possession of assault weapons, vandalism, and two counts of arson after his arrest at his residence in Kingsburg, California.

That said, Mark Broughton, Alan's attorney dismissed the case as "purely circumstantial" after his client pleaded not guilty. He said there was not a single eyewitness, murder weapon, or even a confession pertaining to the case. However, investigators claim they have found enough proof to attach him to the crime.

Fresno County Sheriff Margaret Mims cited “technology and digital data” that helped narrow down the suspect as well as evidence “received just this month” that was “needed to confirm that he was, in fact, the suspect" as she addressed reporters on the day of Alan's arrest. She said there were irrefutable signs that the killings were premeditated, People reports.

Speaking of Alan, Mims said, “We do know that he suspected there was a relationship between Jennifer [whom he was divorcing] and another man, and those are the possibilities that we’re looking at as far as motive.”

Before Alan was arrested, a search warrant and supporting affidavit released this summer detailed a series of allegedly incriminating evidence in the probe. For instance, investigators said that in December Alan had drunkenly "bragged" about setting Houk's vehicle on fire to a relative just a month before her death. According to the affidavit, Alan had also researched how to disable the GPS on his truck in order to hide his location.

On December 11, the bodies of Jennifer and her mother were discovered at Houk's residence in Fresno two days after the incident. It had been reported that Jennifer was just getting her life in order when the homicides took place. She had recently moved in with her mother and filed for divorce from Alan after having recently retired from a 26-year-career in education.

Kelly Rosales, a friend of Jennifer's, spoke to People and recalled seeing Jennifer at her happiest. “She told me she was the happiest she had ever been. You could see it. I ran into her at a restaurant one night, and she had the biggest smile. She was just light. She was just airy,” People quoted Rosales as saying.

Rosales also revealed that Jennifer had recently started seeing someone. Speaking of which, Allison said: “She found someone who was really sweet to her,” and added: “I’m not surprised because she’s so perfect.”

According to Alison, her father had  “turned into this person with no hobbies and no interests and no life of his own.” She also revealed that he was prone to aggression when he was drunk, but had turned sober for seven years until Jennifer told him she was moving on. When Alison's mother decided to leave her father, Alan “was like, ‘I don’t know how she can do this to me,’ very much taking the victim kind of stance. He was pretty delusional about the whole situation.”

According to the search warrant affidavit, Alison also informed authorities about several "incidents of domestic violence" that were never reported. She is now aware of the monumental burden faced by women in abusive relationships, reports People. Her message to other troubled women is that they must take essential steps to protect themselves and must always stay vigilant. “That’s my biggest takeaway,” she said, “and my biggest message.”