Matthew Smith pleaded guilty in court Thursday, admitting to causing the high-speed drunken driving crash that killed Nassau police officer Patrica Espinosa in St. James in the early morning of Jan. 31.

Prosecutors said the 21-year-old faces a sentence ranging from 7⅓ to 22 years in prison.

Smith pleaded guilty to two counts of aggravated vehicular homicide, one count of manslaughter, aggravated vehicular assault, assault and aggravated driving while intoxicated.

According to prosecutors, Smith’s actions on Jan. 30 and into the early hours of Jan. 31 began with a series of stops where he consumed alcohol despite being under the legal drinking age.

Prosecutors said Smith purchased Bacardi rum at a liquor store in Hauppauge without being asked for identification before driving to a friend’s house in Miller Place, where he drank. He later went to Buffalo Wild Wings in Miller Place, where he was served additional alcohol without proof of age, according to the Suffolk District Attorney's office.

Prosecutors detailed how Smith continued drinking throughout the night, including more alcohol at a home, and later at establishments in Hauppauge and Patchogue, including a bar where a bouncer allegedly allowed him entry without checking identification.

Smith then drove a 2017 Chevrolet Silverado pickup truck to Jake’s 58 casino, reaching speeds of up to 100 mph on the Long Island Expressway, authorities said. He was reportedly turned away by security.

By the early morning hours of Jan. 31, Smith continued driving through Suffolk County, failing to stop at traffic signals, according to prosecutors.

Just after 6 a.m., Smith admitted to speeding through a red light at the intersection of Alexander Avenue and Nesconset Highway in St. James going about 70 mph in a 30 mph zone, striking a vehicle driven by Espinosa.

Espinosa died from her injuries. Prosecutors said Smith’s blood alcohol content measured about 0.20% roughly 40 minutes after the crash, more than twice the legal limit.

Smith also signed a waiver of his right to appeal as part of the plea.

Suffolk County District Attorney Raymond Tierney said the guilty plea spares the victim’s family from enduring a trial while serving as a warning ahead of the summer season.

Espinosa’s family declined to comment.

Smith’s defense attorney, Anthony La Pinta, said the decision to plead guilty was made to avoid causing further pain to the victim’s loved ones.

Authorities emphasized the case as a stark reminder of the deadly consequences of reckless and impaired driving.

Matthew Smith is expected to be sentenced on July 20.