Kyrsten Sinema’s ex-boyfriend and former bodyguard said he threw her paintings into her swimming pool in part because he felt disillusioned by her relationship with a major U.S. Artificial Intelligence software developer as the war in Gaza drags on.
Matthew Ammel had a mental breakdown the night that he trashed the former lawmaker’s Cave Creek home, he told The Arizona Republic in an exclusive interview.
“I was pissed at the system and I took it out on her art,” Ammel said. “The American people have no idea how (expletive) up our government is and, like, what our politicians spend their time doing.”
In telephone conversations with The Republic, Ammel, 39, spoke at length about his romantic relationship with Sinema, 50, a former U.S. senator from
Arizona, and described the Aug. 30 incident where he is accused of causing more than $200,000 in property damage to her Cave Creek house.
The rampage included the destruction of paintings, which he tossed in her swimming pool; pricey bottles of alcohol, which were broken; and an expensive mirror, which was smashed.news
Ammel also the man at the center of a "homewrecker" lawsuit brought against Sinema by his ex-wife, and he said he feels the media has wrongly painted him as an adulterer and a bad person.
A former Green Beret, Ammel struggles with brain injuries from his time in the military. His traumatic war experiences are still raw in his mind.
“I'm not a bad guy,” Ammel said. “I'm not crazy. I'm just really (expletive) smart, and I've seen behind the curtains.”
What happened in Cave Creek?
It was the latest turn in Ammel’s custody dispute against his ex-wife that led him to Sinema’s Cave Creek house in August, where their relationship ended with a violent outburst, a police report and a felony charge.
Ammel said he been trying to break up with Sinema, but their lives had become closely intertwined since they began a romantic relationship in 2024.
Since March, Ammel had been living and working as a cowboy at Camp San Luis Obispo, a small California National Guard base.
Several times, though, Ammel found his way back to Arizona. When someone broke into Sinema’s house, he said he drove through the night from California to Cave Creek. When Ammel got sick, he said Sinema encouraged him to come home.
Ammel said he also felt that Sinema, a lawyer and former social worker, had taken control of his custody dispute and made it worse. Sinema was closely involved in preparation for the hearing with his lawyer and his psychiatrist, he said.
The custody hearing went poorly, Ammel said. He confronted Sinema about it when he returned to Phoenix for medical treatment.
"I was angry, admittedly so,” Ammel said. “When I tried to talk to her about it, she abandoned me.”
Sinema left him at her house and went to stay with friends and in hotels around Phoenix, he said.
He trashed the place two weeks later.
Expressing frustration with U.S. foreign policy and the military industrial complex, Ammel demanded Sinema post a video of soldiers from his first deployment helping a man they had shot in Iraq.
In the 7-minute video, which was reviewed by The Republic and which Ammel said was filmed in the spring of 2007, soldiers administered medical care to the bloodied man and picked him up in a helicopter.
Ammel said he wanted Sinema to post the video because “because she works for some of the companies that financially benefit from the genocide in Gaza and the current war we're losing in Iran."
"The same news channels and politicians championing war now were calling us terrorists and racists for our behavior during this time period. (None) of this makes sense. That’s what I was angry about," Ammel said in an email.
Ammel had been drinking, he said, and confirmed that he told Sinema he would throw a piece of her artwork in her swimming pool every 10 minutes until she complied with his request.
He followed through on the threat and dumped 22 of her modern Western-style paintings into the swimming pool, sending her videos and texts as he went, according to a police report.
Ammel also smashed expensive bottles of booze into a mirror and a clock on the wall, leaving a trail of glass in his wake. He said that he intentionally did not destroy any of the art she had been given as gifts from friends.
“I was trying to get her to come back home, or to do something, or to use her connections for good instead of for, to make money,” Ammel said. “I was just going through it, and I don't usually drink, and I got drunk, and I destroyed some of her paintings."
Who is Matthew Ammel?
First as her bodyguard and then as her boyfriend, Ammel got an inside look at the life of a powerful Capitol Hill lawmaker after he met Sinema through former Director of National Intelligence Tulsi Gabbard. In 2022 he joined Sinema's security detail, which at the time was led by Gabbard’s sister.
While working for Sinema, he also trained Navy SEALs, SWAT teams and police officers in the Phoenix area, he said.
Sinema gave Ammel a staff job after they bonded during a two-hour drive over his use of psychedelic drugs to treat his post traumatic stress disorder. He had traumatic experiences during deployments across the globe fighting groups like ISIS and al-Qaida. Sinema had her own trauma, too, he said.
Ammel credits the psychedelic drug ibogaine with saving his life.
His relationship with Sinema turned romantic during a trip to Napa, California in 2024, Ammel and Sinema said in court testimony, a few months after Sinema decided not to run for reelection.
They began a coast-to-coast sexual affair that ended in the dissolution of Ammel's marriage and the headline-grabbing homewrecker lawsuit that has aired their dirty laundry for months.
Sinema’s text messages calling missionary-style sex being “Boring” and offering to guide Ammel through an MDMA experience were suddenly everywhere.
“You understand, Ms. Sinema, don't you, that a wife reading this might get concerned about who is sending her husband that kind of message referring to putting his — her hand on his heart? Can you see that?” a lawyer asked Sinema in a deposition.
Sinema answered “yes.”
Ammel was reluctant to talk about the homewrecker lawsuit his ex-wife filed, but he disputed Heather Ammel’s testimony that Sinema used her status as his boss and a powerful politician to take advantage of him.
“Kyrsten didn't take advantage of me,” he said. “She was nice to me.”
Sinema and Ammel testified at a legislative hearing together, advocating for lawmakers to fund ibogaine trials. She also helped him land a job at Arizona State University, where he said he was working on a new degree program for army combat arms soldiers and a regenerative farming certification. His recent work in California counted toward the ASU job, he said.
But as the war in Gaza continued and a new conflict in Iran began, Ammel said he became disillusioned with the direction Sinema’s post-government career was headed.
Ammel said he accompanied Sinema to an event linked to a top leader of the AI company Palantir, a British American Tobacco Board dinner and the wedding of CNN anchor Jessica Dean to Alex Katz, a senior managing director of government affairs at Blackstone, the world's largest alternative asset management firm.
Ammel felt like he was there as “arm candy,” he said.
“Things changed when I realized that we weren't just like working on ibogaine and like trying to fix the country,” Ammel said.
Sinema has been busy since she left the Senate. She founded the Arizona Business Roundtable and joined the law firm Hogan Lovells Cadwalader. She also embraced the AI industry, launching an AI center at ASU in partnership with OpenAI and lobbying for a failed AI data center in Chandler.
Ammel described feeling disturbed by his last trip with Sinema to D.C., where they attended an event for Palantir CEO Alex Karp. Ammel said it felt to him like a “genocide celebration” of the war in Gaza.
“Kyrsten was there rubbing elbows with Trump's personal lawyer and, like, it was legitimately the most insane thing I had ever seen,” Ammel said.
Sinema and Palantir did not respond to inquiries about whether she has a business relationship with the AI firm.
Karp and other Palantir employees donated thousands to Sinema’s campaign fund in 2022 and 2023, records show. Sinema returned some of the cash when she did not seek reelection.
“She would talk about how she would take bad people's money and use it for good, but like at some point, I didn't see her doing good anymore. She was just doing the bad (expletive),” Ammel said.
What's next for Matt Ammel?
Sinema came home a few days later after the criminal damage happened and filed a police report, while Ammel started a two-week stint in and out of mental health treatment. He was admitted to an urgent psychiatric center for observation, which he said was so chaotic and jarring that it felt “like a Nazi experiment.”
When he was finally discharged from another facility, sheriff's deputies were waiting in the hallway. Ammel was charged with aggravated criminal damage, a class 4 felony in Arizona.
It was not his first felony charge. Ammel was accused of strangling health care workers while he was involuntarily committed at a mental health facility in North Carolina in 2025.
He was released with an ankle monitor and an order to leave Sinema alone.
Now, Ammel is waiting for his next court date and preparing for what he called the worst case scenario: going to jail. He is not worried about jail itself, he said, but he is trying to get things in order for his three children.
Ammel said he checked into the Barrow Neurological Institute one night. Otherwise, Ammel said he has been staying in hotels in Maricopa County, where his only ties lead back to Sinema. He learned they had broken up from a petition to get him hospitalized that referred to Sinema as his ex-girlfriend.
“She was like my only connection to this area, like my kids are in North Carolina, and I've been living in California, so I don't really have any reason to be here other than waiting on a court,” Ammel said.
He also lost his job at ASU. University spokesperson Jerry Gonzalez said Ammel’s fellowship would end Oct. 31.
Ammel said he hadn’t heard from the university about his job, but noted he recently reached out to the psychedelic research professors at ASU for help with his brain.
If he avoids jailtime, Ammel said he would like to return to the California base where he’d been working as a cowboy.
“I had a dumb job, but I'm not dumb. Or crazy, I'm just sick of the system. I want to see my kids and my dog Scout and go back in the Army. I miss them and it every day,” Ammel said.
Stephanie Murray covers national politics and the Trump administration for The Arizona Republic and azcentral.com. She co-hosts “The Gaggle,” The Republic’s weekly politics podcast. Reach her at stephanie.murray@usatodayco.com, on X and TikTok @stephanie_murr and on Instagram @stephaniemurray.news.
This article originally appeared on Arizona Republic: Sinema's ex-boyfriend explains why he trashed her house | Exclusive
