Kylie Rae Harris and 16-year old Maria Elena Cruz were killed in a three-vehicle crash in Taos, New Mexico on Sept. 4

New Mexico Police have completed the investigation into the fatal car crash that killed Kylie Rae Harris and 16-year old Maria Elena Cruz in September.

The Taos County Sheriff’s Office confirmed in a press release on Thursday that Harris, 30, was drunk behind the wheel and driving at incredibly high speeds before her vehicle collided with two others on Sept. 4.

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“Data [from the cars’ on-board computers] showed Ms. Harris’ speed at 102 miles per hour at the time of the first collision event before crossing into the oncoming lane and striking Ms. Cruz’ vehicle at 95 miles per hour,” a spokesperson for the TCSO said.

Authorities also noted that a toxicology report indicated that Harris’ blood alcohol concentration was .28, which is three times the legal limit for impaired driving. Meanwhile, teen driver Cruz had no alcohol in her system at the time of the crash.

“The now-completed investigation supports what we suspected at the time of our initial investigation and my earlier press release that stated alcohol consumption was suspected and speeding was a factor,” Sheriff Jerry Hogrefe said.

In the wake of the authorities’ findings, Harris’ family spoke of their sadness that alcohol contributed to the loss of two lives.

“The family of Kylie Rae Harris received the toxicology report and deeply regret that alcohol contributed to the tragic deaths of Maria Elena Cruz and Kylie,” the family said in a statement to PEOPLE.

“No family should have to endure the heartbreak of losing a child.”

Image zoom Kylie Rae Harris Kylie Rae Harris/Facebook

In September, the Taos County Sheriff’s Office told PEOPLE in a statement that Harris was traveling south on State Road 522 in a black Chevrolet Equinox when she struck a black Chevrolet Avalanche from behind.

The collision initially sent Harris’ vehicle into the northbound traffic lane, where she then collided head-on with Cruz’s white 2008 Jeep, which was traveling north on SR 522 at the time.

The impact of the crash was the cause of death for both Harris and Cruz, who were pronounced dead at the scene, according to authorities. The other driver was not seriously injured in the crash.

“At this time I will say with most certainty that Miss Cruz was an innocent victim of this senseless crash caused by Ms. Harris,” Sheriff Hogrefe said in a statement to TaosNews.com shortly after the incident.

Image zoom Kylie Rae Harris Kylie Rae Harris/Instagram

Days after the fatal accident, Harris’ mother Betsy Cowan revealed to PEOPLE that alcohol was “something [Kylie] struggled with on-and-off over the years,” but declined to share more details “out of respect to both families.”

Cowan also said that the [toxicology report] “results are the same” to her “regardless of what caused it.”

“If you’ve ever had to take defensive driving, they say sleep deprivation, emotions and alcohol are the top three contributors to most wrecks,” she explained. “And so any one of those things could have done it … She had driven 11 or 12 hours that day, and I’m sure that she was exhausted and she was emotionally exhausted. And I think we all know that what that does to you.”

Harris had documented her final moments on social media — tweeting and posting a series of videos on her Instagram Stories just hours before the crash that featured her road trip through New Mexico, where she was scheduled to play at the Big Barn Dance Music Festival in Taos.

The videos were particularly eerie as a teary-eyed Harris discussed how all of her family members who lived in Taos, with the exception of her uncle, had died there.

“Driving these roads — I’ve been driving for 12 hours — you would think that’s so exhausting and boring but like, the last couple of hours driving through the mountains, I’m just remembering my place in the backseat as a little kid when my dad was making these treks here,” she went on. “It was the f— best, and I started getting really sad.”

Image zoom Kylie Rae Harris kylie rae harris/Instagram

A week after the tragedy, the country star was mourned by her friends and family at a celebration of life service, where her 6-year-old daughter Corbie gave a heartbreaking tribute performance to her mother.

The youngster decided to sing Harris’ song, “Twenty Years from Now” alongside country singer Bonnie Bishop — a song Harris initially wrote for Corbie, which revealed her hope that she’d still be around to watch her little girl reach adulthood in the coming years.

That song holds a much different meaning now to Corbie, who was the center of Harris’ world, according to her mom.