New Questions: The Mackenzie Shirilla case is back in focus after disturbing details raised fresh doubts about what really happened

Both prosecutors and Mackenzie Shirilla have made different cases as to why she slammed her car into a brick wall and killed Dominic Russo and Davion Flanagan

Mackenzie Shirilla; Crash scene.
Credit: Strongsville Police Department; Cuyahoga County Prosecutor’s Office

In July 2022, then-17-year-old Mackenzie Shirilla slammed her car into a brick wall and instantly killed passengers Dominic Russo and Davion Flanagan.

Shortly afterwards, authorities began investigating the incident to determine what had happened. Although they initially thought it may have been a tragic accident as a result of drugs or alcohol, Mackenzie had tested negative for alcohol but positive for marijuana at the time of the crash, though investigators determined it did not contribute to it.

When forensic auto investigators examined the crash, they determined that no known malfunction in the car caused it to accelerate. However, they did find that just moments before the crash, the accelerator was fully pressed down, causing the car to reach nearly 100 mph.

As a result of the investigation, Mackenzie was arrested in connection with the deaths of Dominic and Davion. She was convicted of two counts of murder, as well as additional counts for aggravated vehicular homicide, drug possession and possessing criminal tools. She was sentenced to two concurrent 15-year-to-life terms.

In the years since Mackenzie’s conviction, her parents and attorneys have argued that she blacked out as a result of a medical condition. She has continued to advocate for her side of the story, while prosecutors have maintained that she intentionally killed Dominic and Davion as a result of their tumultuous relationship.

Here’s what we know about why Mackenzie Shirilla crashed her car and killed Dominic Russo and Davion Flanagan.

Mackenzie previously referenced car crashes in fights with Dominic

Mackenzie and Dom in The Crash.
Credit: Courtesy of Netflix

Although Mackenzie and Dominic appeared to have a solid long-standing relationship, their partnership worsened in the six months before the crash, according to Ohio Supreme Court documents.

After dating for about four years, their relationship became “strained,” as they were “fighting,” having “disagreements” and breaking up, Dominic’s mom claimed in the docs.

In some particularly tense moments, they’d throw “threats” at each other — including in one July 2022 fight where Mackenzie threatened to break into Dominic’s home if he broke up with her.

Dominic’s mother also told detectives about another tumultuous fight that took place in July 2022. She alleged that Dominic called her and “seemed upset,” so she sent a family friend, Christopher Martin, to “go get him out of the situation that could have been a bad situation.”

While Martin was driving to get Dominic, he heard the two arguing. Martin specifically alleged that he heard Mackenzie say, “I’m going to wreck this car right now.” When Dominic got out of the car, Mackenzie reportedly started “swinging her hands at him.”

Mackenzie Shirilla claims a medical condition caused the crash

Mackenzie in The Crash.
Credit: Netflix

After Mackenzie crashed her Toyota Camry into the brick building, she was temporarily unconscious, while Dominic and Davion were declared dead on scene. Paramedics responded to the scene and assessed Mackenzie before sending her to a hospital to treat her injuries.

Mackenzie has maintained that she has no memory of the crash or the moments leading up to it. She and her parents have since claimed that she experienced a medical emergency as a result of the chronic medical condition postural orthostatic tachycardia syndrome (POTS). According to the Cleveland Clinic, POTS is a blood pressure disorder that causes a number of symptoms when you transition from lying down to standing up, such as a fast heart rate, dizziness and fatigue.

Mackenzie’s mother, Natalie Shirilla, allegedly told medical personnel that her daughter “had a history” of POTS, even though she did not have a confirmed diagnosis. Natalie later testified in court that Mackenzie was diagnosed in 2017 at the Cleveland Clinic.

During her August 2023 trial, Mackenzie’s attorneys primarily argued that she passed out due to a POTS flare-up. Natalie further testified that Mackenzie “experienced a POTS episode a week or two before the crash” and said that “it was really bad, and it hadn’t been that bad in a long time, and she was scared it was going to get worse.”

However, prosecutors questioned how Mackenzie obtained her driver’s license if she had the illness and pointed out that she attested that she did not have “any condition that results in episodic impairment of consciousness or loss of muscular control,” per court records.

Prosecutors argued she intentionally crashed the car as a result of her tumultuous relationship

Judge finds Mackenzie Shirilla guilty of murder.
Credit: WKYC Channel 3/Youtube

While Mackenzie, her lawyers and her parents have claimed that she passed out from a medical emergency, the prosecuting attorneys argued that Mackenzie intentionally crashed the car because she wanted to put an end to her tumultuous relationship with Dominic.

During the trial, prosecutors brought up several volatile fights between the two of them prior to the crash and messages indicating that Dominic wanted to break up.

According to Dominic’s older brother Angelo Russon, the couple had “broken up many times” over the years. However, in June and July of 2022, “Dominic was considering ending the relationship for good,” per court documents.

“Dom tried to break up with her multiple times,” Angelo told police, per footage shown in The Crash. “Dom would have to call Kenzie’s parents, call her mom and stuff, and say, ‘Hey, you need to get Kenzie out of here. She’s refusing to leave my house; she’s being crazy.’ ”

Prosecutors used the couple’s past fights — including videos showing Mackenzie making threats and trying to break into Dominic’s house — as a motive for the killing.

“]Mackenzie’s] past threats and aggression towards [Dominic] provide an important perspective of how [Mackenzie] responds in situations where she is displeased or in disagreement with others,” prosecutors said in court. “Further, the evidence shows that [Mackenzie] was aware of her ability to cause harm to the victims, especially by means of her own vehicle, and how she could use the power of threats and control to ultimately reach the outcome she desired.”

Prosecutors also showed how the car’s accelerator was pressed down to the floor

In addition to sharing Mackenzie’s possible motive, prosecutors also used factual evidence from the car and GPS footage to prove that she intentionally sped up the car and killed the boys.

Forensic auto investigators reviewed the car’s event data record (EDR) — the car’s “black box” system — and found that the accelerator was pressed to the floor with no signs of braking in the five seconds before the crash.

Just three seconds before the car slammed into the wall, “the vehicle registered a small right turn, then a small left turn followed by a ‘significant right-hand turn,’ ” according to court records. At the same time, the gear shift was manually moved from drive to neutral, then back to drive. Mackenzie’s car hit the wall 1.1 seconds later at approximately 98 mph.

The black box also did not find any sort of car malfunction that could have caused the accelerator to have been fully pressed down or stuck.

Prosecutors have theorized that after Mackenzie sped up the car, Dominic and Davion could have tried to stop the crash by grabbing the wheel or gear shift. One of the auto investigators also testified that the right-hand turn could have been Mackenzie trying to get control and hit the passenger side of the car into the wall.

In addition to evidence gained from the car’s EDR, prosecutors further obtained surveillance footage of Mackenzie driving normally before suddenly increasing her speed. Another piece of evidence prosecutors pointed out was that Mackenzie’s GPS data from her phone showed her in the same area as the crime scene just three days prior, per court documents, and alleged that she could have been scoping out a location.