"There was just so much drama -- they would really get into it"

Editor’s note: This story was originally published on Nov. 22, 2016. This week, Alexandria Duval’s murder trial began in the death of her twin sister, Anastasia.

A Florida man who says he once dated one of the twin sisters at the center of an alleged murder in Hawaii stemming from a fatal car crash in May tells PEOPLE he wasn’t shocked upon learning the news.

Keith Weiss says that it has been more than ten years since he and the former Ann Dadow ended what he described as a tumultuous six-month romance. Weiss says his ex-girlfriend and her sister, the former Alison Dadow, had a toxic relationship. (The twins changed their names in 2014: Ann and Alison Dadow became Anastasia and Alexandria Duval, respectively.)

“There was just so much drama,” Weiss tells PEOPLE. “They would really get into it. I remember this one time, the three of us were at the mall, and Ann smacked Alison in the back of the head. Hard. They raged. They went back and forth with each other, pulling hair, pinching each other … it was as if they had blocked everything out around them.”

On Nov. 11, for the second time in seven months, Alexandria Duval, formerly Alison Dadow, was arrested for her sister the alleged murder of Anastasia, formerly Ann, according to a police statement obtained by PEOPLE.

Authorities caught up to Duval in upstate New York, one month after a warrant was issued for her arrest. Alexandria has been indicted in her twin sister’s death; authorities allege she intentionally drove herself and her sister off a cliff in Hawaii on May 29, leaving herself with numerous injuries and killing her twin sister.

Eyewitnesses who’d been driving behind the sisters told police Alexandria and Anastasia appeared to be fighting, and that Anastasia could be seen pulling her sister’s hair, officials have alleged, according to the Associated Press.

The fatal crash followed years of failed business ventures, personal bankruptcies and moves for the sisters, who first made a name for themselves as yoga instructors in Florida only to change their names while living in Utah, according to multiple reports. After her first arrest, Alexandria was cleared by a judge, but new, unspecified evidence has since surfaced, prompting the refiling of charges.

Weiss, a trained chef, says he first met his Ann while he was working at a South Florida restaurant. “When I knew them, they were both in school for court stenography,” Weiss recalls. “Alison came in every night to hang out at the restaurant’s bar and I’d talk to her. Ann came in with her one day, and we hit it off and ended up going out for drinks together.”

On at least two occasions, the twin sisters began fighting inside Weiss’ car, once when Ann was driving. Both of those scuffles were “very intense” and nearly resulted in crashes.

“The first time, Ann was driving, and they just started fighting,” Weiss says. “She let go of the wheel and they were going back and forth with each other, oblivious to the obvious danger and the other cars around us. She almost lost control of the car.”

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Weiss says he split from Ann not long after the second incident. “We were driving home and they wanted me to stop so they could get some wine,” he starts. “But I didn’t want to stop, and Ann, she started kicking my hands … kicking them off of the steering wheel. Alison was kicking the windows and they were screaming, ‘I want you to stop!’ I told them, ‘You’re going to end up killing us.’ They didn’t care.”

Weiss says Alison would tag along on his dates with Ann. “It almost seemed like Alison was jealous of Ann, who always got the guy,” Weiss explains. “Alison was just a bystander, basically. Alison was always the one who was tagging along.”

Weiss says that whenever the sisters would drink alcohol, bad things would happen.

“I once got call from Ann saying, ‘Get over here now … I’m going to kill her,'” Weiss recalls. “She actually started hitting Alison with the phone. I heard it … thump, thump, thump. They were both screaming at each other.

“I get to their apartment and there’s broken glass everywhere from wine bottles and shattered glasses. There was blood everywhere, and the bedroom door was falling off its hinges. Both of them were sitting on the couch when I walked in, and they were like, ‘Hey … how are you doing?’ Alison had a bruise on her face. I asked them if they were okay, and they were like, ‘We’re good, we’re fine. We’re just watching a movie.’ Meanwhile, all around them it’s total destruction. They seemed to not know they wanted to kill each other just minutes earlier.”

A ‘Bizarre’ Yoga Class

The Duval sisters’ drama didn’t wane when they moved to Park City, Utah, where the twins worked as yoga instructors. A woman who took a private yoga class from the siblings describes the experience as “bizarre,” telling PEOPLE a feeling of “one-upsmanship” pervaded the class.

The former student — herself, a yoga instructor — says the class taught by Alexandria and Anastasia Duval in Park City was unlike any other class she has ever taken, and says “their instructions, their demeanor and their energy” were off-putting.

“It was very frenetic and disorganized,” explains the woman, who spoke to PEOPLE on condition of anonymity. “They were teaching at the same time, speaking over one another really fast: ‘Do this, lift your arm, lower your left arm.’ It was honestly one of the most bizarre yoga experiences I had ever had.

“They were giving instructions that didn’t seem to be making much sense to me and at the same time, they were both assisting me. It was a very unusual experience in the yoga community … I’m sure any regular practitioner or teacher would agree.”

Alexandria Duval (left), who is also known as Alison Dadow, and her sister, Anastasia Duval, also known as Ann Dadow
| Credit: Source: Facebook

The onetime student says Park City’s yoga community is “quite small,” so the sudden presence of the tall, blonde Duval twins sparked intrigue.

She attended one of their evening classes, and nearly walked out when “they made fun of my pose,” which she believed was “rude — you never want to demean someone’s personal experience, but also, yoga is about your personal experience.”

She further claims the sisters spoke in “pseudo-spiritual speak that didn’t mean anything” and insists “a lot of their information was incorrect — it was just incorrect.”

Sisterly Rivalry

The former pupil tells PEOPLE that, as a student in the Duval sisters’ class, “it didn’t seem like it was necessarily about me,” noting the twins had “a weird dynamic … I wasn’t sure if they were trying to impress me or each other.”

In the weeks after that single class, she says she reached out to other yoga teachers in the community who had signed up for a session with the twins. “I did hear other students say that they had some similar experiences to me, where they were just bizarre and chaotic and disorganized,” the former student explains.

She believes the twins “were very much loners in Park City.”

“[Both twins] were equally chaotic and based on my interaction with them, just distracted, ungrounded, unorganized,” the woman says.

Alexandria Duval has pleaded not guilty to the charges against her. PEOPLE’s calls to her lawyer, Todd Eddins, were not returned.

• With reporting by HARRIET SOKMENSUER