The death of a Laguna Hills woman who went missing for more than two months before her body was found off Ortega Highway was ruled an overdose and not a homicide, officials announced Wednesday.

Erica Alonso ingested “a lethal combination” of GHB and alcohol, a blood alcohol content level of 0.22, which resulted in her death, Orange County Sheriff’s Department’s Lt. Jeff Hallock said.

Alonso’s father said he met Wednesday morning with sheriff’s investigators who revealed to him that an overdose had killed her.

“It was a big surprise to hear what they told me because I don’t think she did that (overdosed) on purpose,” Isaac Alonso Sr. said.

“If she had a dose of that (GHB), somebody put it in her without her knowing. Even if she was drunk, she never tried that drug. When she did drugs, she did it lightly and wasn’t addicted.

“I have to think about this deeply because it doesn’t make sense to me,” Alonso Sr. said.

He also couldn’t fathom why someone didn’t notify the authorities if they were with his daughter when she was in medical distress.

“They saw that she was dying, how come they didn’t call 911?” Alonso Sr. said. “We are supposed to help anybody stay alive.”

Erica Alonso was last seen by friends during the early-morning hours on Feb. 15 after she attended Sutra nightclub in Costa Mesa.

Months went by without contact from her; her car was found March 25 in Aliso Viejo. Family and friends plastered South County with missing person fliers and led candlelight vigils.

Then a group of California Department of Transportation biologists found her body April 27 in a dirt area about a mile east of the U.S. Forest Service fire station off the Ortega Highway near San Juan Capistrano.

Coroner officials performed an autopsy April 29 and could not initially determine the cause of death, but a toxicology report revealed the answer Tuesday.

GHB, or gamma-Hydroxybutyrate, is a drug commonly associated with nightclubs, like the one where Alonso had been hours before her disappearance, that causes sedative-hypnotic effects that can lead to death, according to the National Institute on Drug Abuse.

“Combined use with other drugs such as alcohol can result in nausea and breathing difficulties,” according to institute research.

“Based on the totality of the investigation, including interviews, evidence collection, autopsy and toxicology results, investigators do not believe Ms. Alonso was the victim of a homicide,” Hallock said in a press release.

It is still unclear how her body ended up in the remote location and who put it there, questions that may be answered in the future although the death is no longer being investigated as a homicide, Hallock said.

“The investigation is still ongoing,” Hallock said. “Although we know the cause of death, the manner of death is still under investigation.”

Officials said it is still undetermined how long Alonso’s body was laying in the dirt embankment based on the condition it was found in.

“What happened after she died is still essentially a mystery,” Hallock said.

Alonso Sr. said he wants video cameras installed on Ortega Highway at the entrance of Lake Elsinore and Antonio Parkway in San Juan Capistrano to help reduce crime in those areas.

He also favors stiffer penalties for concealing a body following an accidental death.

Contact the writer: 714-796-7802 or aduranty@ocregister.com