The mother of three young children who drowned after she drove her car into a manmade lake told police she fell asleep behind the wheel before the crash, waking only after feeling water surge into her car, court documents show.

Amber Turley, 26, told officers she tried to pull her three sons out of Brewer Lake during an early morning thunderstorm but lost sight of them. Officers found the boys, limp and not breathing, after the diaper of her 2-year-old son floated to the surface, according to a police report.

The boys -- Aaron, 8, Alex, 7, and Anthony, 2 -- were pronounced dead at a hospital.

Turley faces three counts of felony endangerment of a child in the April 19 crash. Toxicology reports from the state Crime Laboratory show a blood sample collected from Turley after the crash tested positive for marijuana and benzodiazepines, a class of drugs that include sleeping and anxiety pills.

Turley also had a blood-alcohol level of .05, the crime lab reported. The legal limit in Arkansas is .08.

In an autopsy report for Aaron, a medical examiner wrote in the margin: "If mother was intoxicated, may rule as homicide." The medical examiner who performed the autopsy on Anthony wrote: "Case is strange at best as to circumstances and may represent homicide, neglect or worse."

Turley's lawyer, Dale Lipsmeyer of Morrilton, declined to comment Wednesday.

Before the crash, witnesses told police that Turley attended a party with her children in Conway County, where she had about 2 1/2 glasses of cola and cinnamon schnapps. Partygoers also passed around a marijuana pipe that was refilled "two to three times," the report shows.

Turley quit drinking about two hours before leaving the party to drive her boyfriend home, witnesses said. The police report shows he sent her a text message asking her to have a good night.

"At approximately 3:13 a.m., (the boyfriend) received a message back from her that read: `U to TTYL,"' an Arkansas State Police report reads. "That was the last time he heard from Turley."

Minutes later, police say, Turley missed her turn on the way home. Instead, she drove down Johnny Walker Road, which led straight into Brewer Lake. Police found her car turned sideways in the lake, 100 feet (30 meters) from the shore.

Police say Turley later told investigators that she hit her brakes before reaching the water, which contradicts her initial statements to officers as she screamed for her children alongside the darkened lake. The case file in the clerk's office included the first page of her interview with the Arkansas State Police but nothing else.

Turley remains free on $5,000 bond. Her arraignment is scheduled for Sept. 8.