‘I am not a violent man.’ Rigby man responds to deaths on his property and repeated abuse allegations

RIGBY — A Rigby man has been arrested multiple times for alleged violence against women dating back to 2011, with six cases within the last year and a half.

There have also been three deaths on his property, although he has not been charged or listed as a suspect in connection to any of them.

Matthew Beck, 41, has been accused of many violent allegations over the years, including strangulation, aggravated assault, aggravated battery, and more. Some of the charges have been dismissed, and others are ongoing.

The Jefferson County Sheriff’s Office confirmed they have dealt with Beck many times.

“Jefferson County Sheriff’s Office has had numerous interactions with Beck. Several of these have included charges for violations of no-contact orders or civil protection orders,” says Jefferson County Sheriff’s Office spokesperson Jennifer Fullmer. “One issue deputies have run into is victims who have not cooperated with deputies or did not follow through with court proceedings. Our office takes these matters seriously, and we do everything in our power to get domestic violence suspects prosecuted.”

In the following case summaries, court documents allege that multiple of Beck’s alleged victims either did not continue with the court process for unknown reasons, or claimed to be threatened by Beck into dropping the charges.

EastIdahoNews.com reached out to Beck, who denied abusing the women. When asked, he stated that the only time he was violent toward any woman was in attempting to defend himself.

“I’m not a violent man. I’ve never harmed anyone out of rage, revenge, or cruelty,” said Beck in a statement to EastIdahoNews.com. “When I’ve had to defend myself, it was because I was literally being shot at, stabbed, or backed into a corner. And even then, I used only what force was necessary. Nothing more. Nothing less.”

There have also been three confirmed deaths on Beck’s property located on the 500 North block of 4200 East in Rigby.

According to Beck, his friend died from an overdose at his home. It is not clear when the man died.

Heather Arehart was found deceased on the property in May 2021, inside a shed, after being reported missing. Her body was found on the same day as the Rigby Middle School shooting, so the Bingham County Sheriff’s Office took over the case.

RELATED | Investigation underway after missing woman is found dead on Jefferson County property

Arehart’s cause of death was later ruled a drug overdose, and officials say foul play was ruled out.

Last year, Brook Thieman was found deceased inside a motor home on Beck’s property after the house caught fire on July 7. The Jefferson County Sheriff’s Office says they are investigating her death as a homicide, but noted there are no suspects at this time, including Beck.

RELATED | Woman’s body found inside burning motor home

RELATED | Local woman’s ‘suspicious’ death being investigated as a homicide

None of the women who have died are victims in the following criminal abuse cases.

Shots fired

In 2011, Beck was charged in Jefferson County with felony aggravated assault with a deadly weapon and felony attempted strangulation.

According to Idaho’s online court system iCourt, the records for this case were “destroyed” in February 2020, “provided that complete case histories are preserved through imaging.”

EastIdahoNews.com submitted a public records request to the Jefferson County Sheriff’s Office and obtained the details.

On Dec. 31, 2010, deputies took a report from a woman who said she was lying in bed on Dec. 30 when Beck tried to touch her, and she pushed his hands away.

Beck tried to take the woman’s clothing off and “would not let go,” so she “punched (Beck) in the stomach,” according to court documents.

Beck then “grabbed her arm and wrapped it around her neck using her elbow for leverage to choke her,” according to police reports. The victim screamed that Beck was hurting her, and Beck allegedly said she had “not felt pain yet.”

According to police reports, the victim could not breathe and tried to reach for her phone, but Beck “grabbed her by her hair and then slammed her on the ground and broke her cell phone.”

She stood up, but Beck allegedly “slammed her against the wall and then put his hand around her throat” before throwing her onto the bed, where he “put his elbow into her throat and applied pressure.”

Police reports say the victim tried to get away and started screaming, so he “covered her mouth with his hand.” Beck sat on the bed and reportedly “made a comment that he would shoot her.”

He then allegedly “grabbed a loaded M-4 rifle and pointed it to her head” before raising the gun “two to three feet above her head and fired a shot into the wall.”

Beck allegedly then put the gun down and went to bed. The victim told deputies Beck had “extensive military training through the United States Army,” and that he was a “sniper for the Army, and he suffers from post-traumatic stress disorder and is 100% medically discharged.”

According to documents obtained by EastIdahoNews.com, Beck has at least one Purple Heart award from being injured during active duty in 2007.

Deputies said the victim had a “bruised right ear, and bruises on her right arm from the alleged altercation.” The woman told deputies that Beck had “a lot of rifles in the home and is very dangerous.”

They took Beck into custody and booked him into the Jefferson County Jail on a $60,000 bond.

During an interview with Beck, he claimed he had been drinking, and when he was going to bed, the victim began arguing with him. He stated she “became upset and started hitting him,” so he “used basic self-defense techniques he learned in the Army.”

According to Beck, he “grabbed the rifle and shot a hole in the wall to calm the situation.” He told deputies that “shooting the round in the wall was a riot-control technique that he had learned in the Army” and that the victim “was not close to him when he fired the shot.”

The case was dismissed by former Jefferson County Prosecutor Robin Dunn on March 18, 2011. The reason for the dismissal is unclear.

RELATED | Former prosecutor Robin Dunn sentenced to prison for drug trafficking

‘Stomped her face’

Thirteen years later, Beck would see his next local criminal case.

According to court documents, Idaho Falls Police were called to an apartment on March 9, 2024, and found a 41-year-old woman lying on the ground. She said that Beck, who did not live there, had arrived, and she asked him to leave.

Beck reportedly refused to leave, and the two got into a fight. The victim said she was holding a knife when Beck “grabbed her by her hair and threw her to the ground.”

According to the victim, Beck “punched her, and once she was on the ground, stomped her face several times with his foot.”

Police say they did not see a knife in the area, but that the victim had “very obvious injuries to her face” including a “shallow laceration on her forehead and considerable swelling around the laceration,” which police say was “apparent that the injury was from a blow to the head with a blunt object or fist.”

The victim was then transported to Idaho Falls Community Hospital.

Officers met with Beck, who claimed he went to the victim’s apartment because she was “talking s***.” He stated the victim opened the door and “punched him in the face near his left temple/eyebrow,” then tried to stab him with the knife.

Beck said he pulled her hair and “forced her to the ground to avoid being stabbed,” but the woman tried to stab him in his groin, so he “stomped on her head two times.”

He allegedly told police, “If he had a gun, he would have shot her.”

Officers met with the victim at the hospital, who said she wanted to pursue charges against Beck.

In May 2024, Beck was charged in Bonneville County with felony aggravated battery and misdemeanor failure to depart. Beck was arrested on June 7, 2024, and booked into the Bonneville County Jail on a $2,500 bond.

The misdemeanor was dropped on Nov. 18, and Beck pleaded not guilty to the felony on Jan. 21, 2025. He is scheduled for a status conference on July 21. If convicted, he could face up to 15 years in prison.

At the hotel

Three months later, on Aug. 17, police were called to the Holiday Inn Express for a 39-year-old woman, who had a possible broken wrist from “being thrown across the room by Matthew Beck.”

According to court documents, the victim said Beck had “strangled her” and was “banging her head on the ground of their hotel room, causing her to lose consciousness.”

Police say the victim “had a swollen wrist” and “bruising on (her) neck.” A guest in another room reportedly told police, “it sounded like a female was getting beat inside the room.”

Jefferson County deputies detained Beck at his home in Rigby until IFPD took him into custody. Beck was charged in Bonneville County with felony attempted strangulation and felony domestic battery with traumatic injury. He was booked into the Bonneville County Jail on a $45,000 bond.

Court minutes from Beck’s preliminary hearing say the court “does not find probable cause, and dismissed the case without prejudice.”

Both charges were dismissed by the court on Sept. 13.

‘Three puppies in a cage’

Five months later, on Jan. 16, 2025, Beck was charged in Bonneville County with a misdemeanor violation of a domestic violence protection order. Beck was given a $2,500 bond and was released on March 4 after pleading not guilty.

The victim in this case was the same woman who alleged that Beck “stomped on her head” in March 2024. She called police on Jan. 16 to say he had contacted her after being served with a no-contact order.

Court documents say the victim had recently been in court to testify about the alleged violence she suffered from Beck, and had taken her therapy dog with her. Around 8 p.m., she reportedly got a message from Beck that showed “a picture of three puppies in a cage.”

The victim told police she “felt this was a kind of threat to her therapy dog that had been present with her in the courtroom.”

Police attempted to get in contact with Beck but could not, so they issued a warrant for his arrest on Jan. 31. It was served on March 4. Beck is expected to appear for a jury trial on July 18.

Incident on the interstate

Two months after that, on March 8, an Idaho State Police trooper responded to a report that someone “witnessed a male physically beating the female inside a truck” on southbound Interstate 15 near milepost 113.

The trooper found the truck and initiated a traffic stop, noticing the woman “appeared to be shaken and uncomfortable” and had “marks on the front of (her) neck” while she “appeared to have a raspy voice.”

The woman identified Beck, and initially told the trooper there “was no physical altercation and they had only been in a verbal argument.”

Beck claimed that the woman “bit him as a reaction to getting choked the f*** out by him while trying to save her life.” He then said the woman tried to jump out of the moving car while driving down the highway, and he “choked her to pull her back in.”

The trooper writes that Beck had a “circular pattern mark from individual teeth around a perimeter of abrasions and contusions around his right pectoral.”

A sergeant searched the car and found three THC vaping devices and a Glock 43 firearm.

Court documents say Beck is “prohibited from possessing a firearm due to the conditions of his no-contact order.” Beck allegedly admitted to possessing the firearm and was arrested.

The woman was then told she was being put under arrest for felony domestic battery.

She then said, “(Beck) grabbed me by the throat.” When asked why she didn’t say this before, she replied, “because I’m f****** scared” and stated Beck was “screaming and yelling” and “grabbed me and pinned me down to the f****** armrest, put all his weight on me, and that’s when I bit him on the chest.”

The woman was transported to the Bonneville County Jail and and charged with two counts of misdemeanor possession of a controlled substance.

Beck was charged in Bonneville County with felony attempted strangulation, misdemeanor possession of a controlled substance, and misdemeanor domestic violence without traumatic injury. He was given a $30,000 bond, but it was later increased to $75,000. He was then sent to pre-trial supervision on March 19.

Beck is expected to appear for a jury trial on July 18.

Auto parts store

Twelve days after the last incident, on March 31, Rigby Police officers were dispatched to O’Reilly Auto Parts on March 20 for a report of a customer, identified as Beck, who “held a female staff’s arms above her head and would not let her go.”

When officers arrived, they were met by the victim, who was crying.

Beck reportedly asked to see some bruises on the employee’s arms, which she said were caused by anemia. The woman held her arms out, and Beck “made a joke about getting handcuffed to a bed” before he allegedly “grabbed both of her wrists and held her arms above her head and wouldn’t let them go.”

The woman told police that Beck and a woman with him were laughing during this, and she “froze.” She said she did not know Beck.

When officers spoke to the manager, he said Beck was a frequent customer and had been getting deliveries from O’Reilly’s, but that they stopped delivering to him because the manager “did not want his drivers out there.”

The manager told police that Beck came back into the building after the alleged assault and was told he was not welcome at the store anymore.

At that time, the victim did not want to press charges and said she was “worried about retaliation.”

The manager told police he wanted Beck to be trespassed from the property, so a notice was filed that Beck was no longer allowed at the store.

On March 25, the victim contacted police, wanting to press charges after Beck allegedly “called into the store trying to explain his side of the story and attempting to get the written notice of trespass from the store dropped.”

The victim also told police that the woman with Beck came into the store “trying to downplay what happened and to get the notice of trespass dropped.”

Beck had also tried to add the victim as a friend on Facebook and reached out to her on Facebook Messenger, according to police reports.

Court documents say the victim was “visibly upset” and said she was afraid of retaliation. Officers then gave the woman information on how to seek a civil protection order.

Beck was charged with misdemeanor intentional and unlawful battery. He was arrested and booked into the Jefferson County Jail, being given a $300 bond.

He posted bail and was released on April 11.

He has pleaded not guilty and further court hearings have not been scheduled.

Beck’s statements on the deaths

In an interview with EastIdahoNews.com, Beck denied having any involvement in the deaths on his property.

“People want to whisper about the deaths that occurred on my property,” says Beck. “I understand how it looks from the outside, but let me tell you the truth.”

According to Beck, the first death on his property was a good friend of his, and the man passed away after mixing alcohol and prescription medication.

“(He) was one of my best friends—a fellow disabled veteran. The morning we were supposed to go to court to help him get off probation, he overdosed after a night of drinking and accidentally mixing his prescription meds,” says Beck. “I was literally ironing our clothes when it happened. I lost a brother that day.”

As for Arehart, Beck says she died of a pill overdose and he found her body after coming home from a camping trip.

“Days after a camping trip, I returned home to find her lifeless. The same day as the Rigby school shooting. So while I was grieving the love of my life, I was being interrogated for over 12 hours by every agency under the sun,” says Beck. “They treated me like a criminal until the toxicology report proved what I already knew—she overdosed on fentanyl, meth, heroin, and other substances. The sheriff himself drove me home.”

When it comes to Thieman’s death, Beck says he doesn’t know what happened, but he helped others to evacuate the home near the fire before they realized Thieman was inside the locked trailer.

“She and her boyfriend asked to stay for a short time, and I said yes out of gratitude and trust. The morning of the fire, I heard them fighting. He stormed off. Later he returned, and I assumed things had cooled down. I went back to sleep. I was woken to police and firefighters yelling, my home was in flames,” says Beck. “I ran outside in my boxers, helped evacuate two babies, my niece, her husband, and my dogs. When I reached the RV, flames were pouring out. Brook was inside. The door was locked. No one could reach her in time.”

Beck’s statements on violence

According to Beck, the ongoing and dismissed cases have a different story when told from his perspective.

“I’ve seen more loss than most people will face in a lifetime,” says Beck to EastIdahoNews.com. “But I don’t hide from it. I don’t run from it. And I don’t lie about it.”

In the case from December 2011, Beck tells EastIdahoNews.com that he was asleep with a CPAP machine after being saved by Search and Rescue following being stranded at Blackfoot reservoir in “chest deep snow”, when a woman “thought it would be funny” to shoot a gun toward him.

“I jumped out of bed, and I shot back at her and silhouetted her. I said, ‘”Do you want to play that f****** game?'” says Beck. “I know the game. I know, and I got charged with it.

In the case from March 9, 2024, Beck says he wanted to visit a woman at her home, so he showed up and knocked on the door.

“When she comes out, (she said) ‘I’m gonna f****** stab you,'” says Beck. “So I’m like, okay, haha. Why are you doing this? Like, haha, you know? And (she said) ‘”No, I’m f****** serious.”

According to Beck, the woman was “cracked out on meth” and punched him in the face, ripping his retina in his left eye and leaving him partially blind.

“When that happened, it bounced my head off the wall,” says Beck. “She tried to stab me in the gut with a knife.”

Beck says the woman tried to stab him but missed and stabbed him in the hand.

Beck claims he tried to defend himself and punched the woman in the face before trying to leave. At this point, Beck says the woman chased Beck out the door and tackled him, stabbing him four times in the back of his leg.

“I kicked her, got her off me, and I ran out the door, blew through the door and broke the glass door in the frame and knocked the whole d*** thing off the wall,” says Beck. “I reported it to Jefferson County and Bonneville County. She told the cops that she had not hit me.”

Beck claims the stab wounds ended up putting him into the hospital with an infection because the woman allegedly “smeared the knife with dog s*** and methamphetamine.”

In the case from Aug. 17, 2024 Beck claims he was in a hotel room with a woman who was intoxicated, and he declined her sexual advances, causing her to attack him.

“She just looked like somebody popped a switch,” says Beck. “She jumped off of me, grabbed the phone on the nightstand in the hotel room, went to smash it, and realized it was her phone,” says Beck. “She threw it at me, grabbed my phone, smashed it, and then went running towards the exit and took the door head on and bounced and hit the other door that KO’d her.”

In the case from on March 8, 2025, Beck claims a woman threatened to kill herself by jumping out of his truck while he was driving.

“She opened the door and tried to jump out of my truck going on the highway. I slammed on the brakes, cut across traffic, (and) I had already reached over and grabbed her,” says Beck. “She’s dangling out of my truck, and I’m not even looking. I don’t care if I hit something or whatever… you know my old lady’s about to get f****** get sucked under and become roadkill.”

According to Beck, he pulled the car over and decided to turn back around and go home. On the way back, they were pulled over by the Idaho State Police.

“She tells them some bulls***,” says Beck. “And I’m like no, she f****** godd*** tried to commit suicide. Well, they believed her.”

In the case at O’Reilly’s on March 31, Beck says the incident was not violent.

“There was a young girl, early 20’s sitting there. She has her arms extended out, and it looks like two-inch strap bruises going across her wrists and across her forearms,” says Beck. “I asked her, I said, ‘Oh my God what happened?”

Beck says the girl stated she didn’t know what happened, allowed him to look at the bruises, and that was it. Later that day, the store called and told Beck he was no longer allowed in the store.

“I didn’t do anything bad, nothing,” says Beck. He then called O’Reilly’s corporate and complained, telling them nothing happened. The store reportedly told Beck there were assault allegations, and he was later arrested for battery.

According to Beck, who is a U.S. Army veteran, he recently attended multiple inpatient classes with the United States Department of Veteran’s Affairs, including grief recovery, anger management, PTSD treatment, and more.

“I’m just trying to get some treatment. That way, if I do get found guilty in trial, I don’t end up killing myself in prison or something like that,” says Beck. “The only thing I’m guilty with is protecting myself, defending myself,” says Beck. “Like, I was in the military. I did three f****** tours.”

What happens now?

Beck has not pleaded guilty in any of these cases and has multiple hearings scheduled in most of them.

EastIdahoNews.com has tried to contact two of his most recent public defenders in Bonneville and Jefferson counties, John Malek and Trent Grant, for comment, but we have not yet heard back.

We also reached out to Bonneville County Deputy Prosecuting Attorney Alan Embree, who is prosecuting Beck’s most recent Bonneville County case, and Sam Angell, who is prosecuting Beck’s most recent Jefferson County case. We have not heard back, but will update this story if we receive any statements.

Though Beck has been charged with these crimes, it does not necessarily mean he committed them. Everyone is presumed innocent until they are proven guilty.

EastIdahoNews.com will continue to follow these cases.