What truly happened before police arrived at a Patty Jewett neighborhood home to find one person dead and two injured from stab wounds on Halloween last year will be up to a jury to decide, an El Paso County judge ruled last week.

Matthew Regnier, 34, is charged with several felonies, including first-degree murder, after allegedly fatally stabbing his brother-in-law and injuring two more family members.

Judge Dennis McGuire bound over, or accepted, the charges against the former Monument Academy teacher this week during his two preliminary hearings, which also revealed new details about the case.

When officers arrived at the house in the 1400 block of El Paso Street on Halloween night, a severely injured woman answered the door, telling officers in Spanish that someone had a knife, Colorado Springs police officer Michael Delgado testified.

Behind the woman, they found Regnier, naked and covered in blood, while holding an inconsolably sobbing toddler, according to court documents.

“No one was expecting what was behind that door,” Delgado said.

At the preliminary hearings, both sides appeared to agree about the moments that led up to the deadly turn of events, which transpired in a bedroom of the home.

According to testimony given Wednesday, the injured parties included Regnier’s wife, mother-in-law and brother-in-law. Regnier and his wife, who married in December 2021, were reportedly heading for a divorce, according to Regnier’s Facebook profile.

Colorado Springs police detective Stephen Aulino, testifying about statements from the wife, said she told police the night started peacefully, with the family giving out Halloween candy to neighborhood children.

At some point, Regnier asked to take his son to bed, but the child was allegedly accustomed to sleeping with his mother, the wife told Aulino. When the son started to cry, the wife came in and asked to comfort the 2-year-old, but Regnier allegedly refused to allow it.

Things then began to escalate, the wife told Aulino. The detective testified on cross-examination that the wife called 911 at some point – one of two 911 calls placed from the address about the altercation that night – and reportedly put her hands around Regnier’s neck in an attempt to get the child back.

The two other victims came into the room to assist, and at this point, Regnier is alleged to have pulled out a knife and stabbed the trio, each several times.

Regnier maintained his stance that he was acting in self-defense during interviews with detectives, officers testified Thursday.

Regnier told detectives he recorded a video of the incident when things began to escalate, but another detective testified the video’s angle primarily focused on a bedroom wall that became splattered with blood.

Regnier also reportedly told detectives that the attack was seemingly random, and he had only gotten up to change his son’s diaper when the trio came in and “punched and choked” him, Delgado said.

The brother-in-law, later identified as 31-year-old Raymundo Cabrera-Medina, died as a result of the multiple stab wounds to the face, neck, chest and hands. The mother-in-law and wife also suffered significant injuries, including a cut to the mother-in-law’s wrist that one witness said looked “like an amputation,” according to Thursday statements from the prosecution.

According to a GoFundMe page made for the victims, the women were released from the hospital on Nov. 12. 

Regnier sustained a finger injury, as well as documented injuries to his groin area that the defense says he suffered during what they couch as self-defense, but was otherwise unscathed. Despite that, Delgado said Regnier was coated “head to toe” in blood when officers arrived.

Before McGuire’s ruling to accept the charges for trial, Regnier’s wife gave a statement to the courtroom.

Her voice measured and breathless, and at times barely a whisper, Jessica Cabrera Regnier said that she was lucky to survive the injuries inflicted that night, in an attack that claimed the life of her brother.

She still struggles with anxiety and fear, and her young son still has nightmares – on the nights he’s able to fall asleep.

“He’s scared,” said Cabrera Regnier, adding Thursday that she’d only recently learned that she “coded” – or flatlined – that night, before doctors were able to bring her back. 

“I have nightmares and everything, just because I wanted to try to get ahold of my son who was crying,” she told the court. 

Matthew Regnier’s next appearance in court is scheduled for March 23, at which point he is expected to enter a plea. As of Friday, Regnier remains in El Paso County jail on a $1 million bond, inmate records show.