A Sewickley man who was driving 88 mph on a snow-covered back road when he crashed his car, killing his girlfriend’s sister, pleaded guilty on Monday to homicide by vehicle.

Luke Flowers, 20, will be sentenced by Allegheny County Common Pleas Judge Kelly Bigley on Jan. 9.

As part of an agreement, Flowers, who said he just completed his first year of college, also pleaded guilty to aggravated assault by a vehicle, seven counts of driving under the influence, reckless and careless driving.

There is no agreement on his sentence.

According to the criminal complaint, Flowers was driving an Audi Q5 when he crashed at 10:14 p.m. on Christmas Eve, 2022.

His girlfriend, Ainsley Kiggins, who was the front-seat passenger, was injured. Her sister, Camden Kiggins, 20, who was in the back seat, was taken to a local hospital in critical condition and died several hours later.

According to Allegheny County Police, Flowers’ vehicle was found about 30 feet off the side of Fern Hollow Road, up a hill and between two trees.

Flowers told police he arrived at Ainsley Kiggins’ house at 6:30 p.m. after dinner, and the two hung out before going to Sheetz with her sister around 9 p.m.

They ate in the parking lot before heading back to the Kiggins’ house.

Flowers told police the road was covered in a mixture of snow and slush and that he was following tracks as he drove.

“Flowers said he hit the guardrail and that the vehicle felt like it flipped over, but he was not sure,” he told police.

When he woke up, he continued, he called out, and only Ainsley responded.

Ainsley told police that Flowers had two to three glasses of wine at dinner earlier in the evening before arriving at her house.

She said she also knew of him smoking marijuana in the past.

Flowers’ blood alcohol content was 0.096%, and he had marijuana in his system, police said.

Detectives charged him several months later. According to the vehicle’s computer data, Flowers was traveling 88 mph 3.5 seconds before the crash.

The speed limit on the two-lane road is 35 mph.

Bigley revoked Flowers’ bond at the end of the plea hearing.

His defense attorney, Robert Del Greco, called Camden Kiggins’ death a tragedy. Her obituary said she was a sophomore at Ohio University.

“Today, Luke Flowers accepted responsibility for for his actions that he profoundly regrets,” Del Greco said.

Correction: An earlier version of this story misstated the timing of Kevin Flowers’ arrival at Ainsley Kiggins’ house. Police said Flowers told investigators he arrived after dinner.