Erica Alonso had BAC level of .22 and GHB in system at time of death

SANTA ANA, Calif. (KABC) -- A Laguna Hills woman who went missing in February and was later found dead in the Cleveland National Forest died from an overdose, toxicology reports confirmed Wednesday.

Erica Alonso had a lethal dose of alcohol and GHB in her system at the time of her death, sheriff's officials said. Her blood-alcohol level was .22 - nearly three times the legal driving limit.

"GHB could be classified as a party-type drug, and it gives a sedative, euphoric-type feeling," Orange County Sheriff's Department Lt. Jeff Hallock said.

The cause of death is officially an overdose, but the manner is considered undetermined, Hallock said.

Meanwhile, Alonso's father is stunned.

"We were not expecting them to tell us something like that, we were not expecting that at all," said Isaac Alonso Sr.

The findings raise many questions for her family: Did someone slip her the drug or did she take it willingly?

Alonso disappeared on Feb. 15 after she got into a fight with her ex-boyfriend and left his Irvine home in the middle of the night. The two had celebrated Valentine's Day at Sutra Lounge in Costa Mesa earlier that night. She was 27 years old when she disappeared.

Her white 2014 Honda Civic was found in the Glenwood Park neighborhood of Aliso Viejo on March 25.

Biologists working for Caltrans found her decomposed body on April 27 in a dry creek bed on Ortega Highway near Hot Springs Canyon Road, one mile east of the San Juan Capistrano-Fire Ranger Station.

Investigators do not believe Alonso was the victim of a homicide, but "the investigation is ongoing as to what happened and how she ended up off Ortega Highway," Hallock said. "We believe that she died at another location and the body was taken to that location."

So far, authorities say they've interviewed numerous witnesses, including her ex-boyfriend.

Her father wonders if she might still be alive if someone had called for help in time.

"To do the right thing is to call 911 or someone for help, but not just to get rid of the body and try not to get involved," he said. "My daughter had a life. She had plans and they just cut them off."

Concealing a body after someone accidentally dies in considered a misdemeanor. Alonso's father says he plans to fight to make it a felony instead.

Anyone with additional information is asked to call the Orange County Sheriff's Department's Homicide Unit at (714) 647-7055 or (714) 647-7000. Anonymous tips may also be submitted to Orange County Crime Stoppers at 855-TIP-OCCS (855-847-6227) or at occrimestoppers.org.