The coroner says 17-year-old Brissa Romero was under the influence of alcohol and THC when she drove her car into a Vernon Hills pond before being found dead last month.
The Lake County Coroner’s Office confirmed to Lake and McHenry County Scanner on Wednesday that it had recently received toxicology test results for Romero.
The tests, which were analyzed by an independent laboratory, showed Romero had a blood alcohol content of 0.16.
Her blood alcohol content was two times the legal driving limit for those who are 21 and older.
The coroner’s office also said Romero’s THC levels were consistent with recent use.
Her THC reading showed 7.4 nanograms per milliliter. The THC limit for driving in Illinois is five nanograms per milliliter.
The coroner’s office listed Romero’s official cause of death as drowning in a retention pond with ethanol intoxication as a contributing factor. Her manner of death was determined to be an accident.
Romero went missing on December 4 on her way to a holiday work party at Bowlero in Vernon Hills, according to Carpentersville Deputy Police Chief Kevin Stankowitz.
Her body was located in a retention pond near Executive Way and Lakeview Parkway in Vernon Hills on December 12.
Vernon Hills Chief of Police Patrick Kreis said during a press conference last month that an analysis of Romero’s cellphone data led investigators to the pond.
A police supervisor arrived on the scene and met with a resident, who had been walking around the bank of the pond.
The resident pointed out a backpack that was floating along the edge of the pond, Kreis said.
The officer found the backpack belonged to Romero, a Carpentersville resident.
Kreis said Romero’s 2008 Nissan Rogue was located by fire crews in the afternoon on December 11 submerged in the pond, but the girl was not inside it.
Investigators found video footage from a fast food restaurant approximately a mile away from the pond that captured Romero parking her vehicle on the evening she went missing.
She walked into the restaurant and walked out of it by herself, the video showed.
Kreis said she then drove away from the restaurant about 15 minutes before her phone last pinged to the pond.
The video from the restaurant is one of the reasons investigators believe Romero was operating the vehicle when it drove into the pond.
Kreis said the deepest part of the pond is just under 20 feet, which is also the area where Romero’s vehicle went into.
“The vehicle traveled as much as 60 feet into the pond,” Kreis added.
The police chief said the area where the car went into the pond was at a “T” intersection.
“From the preliminary review of what happened, it really appears like this is a case where a driver, unfamiliar with the area, failed to navigate a turn and went through the intersection, down an embankment, into the pond,” Kreis initially said last month.
Romero was a graduate of Barrington High School and a current student at Harper College in Palatine.