Even though the medical examiner ruled Olson's cause of death a suicide and the two girls homicides, an official said it's still too early to say who killed the younger victims.
Three people — found shot to death inside a luxury home near San Antonio last week — were classified as a suicide and two homicides, officials said.
The medical examiner and sheriff identified two of the dead as Nichol Olsen, 37, and her daughter Alexa Montez, 16. Investigators are still trying to verify the identity of a 10-year-old girl through dental records, but Bexar County Sheriff Javier Salazar said detectives believe they know who she is.
Even though the medical examiner ruled Olson's cause of death a suicide and the two girls homicides, Salazar said it's still too early to say who killed the younger victims inside the Anaqua Springs Ranch subdivision, northwest of San Antonio.
"So the fact that Nichol Olson's death, for right now, has been ruled a suicide, we can't just say, 'Oh well, she must have been the one who did this to these two little girls,' " he said.
"We still have to go out and find out who it was that killed these two young ladies. The evidence may lead us right back to somebody within the house, but it may not. And it would be irresponsible of us to come to that conclusion at this point when there's so much investigation being left to do."
Deputies are still combing through cell phone records, GPS data, surveillance video and gunshot residue tests, officials said.
"My investigators are being completely thorough, up to and including, not ruling out the fact there might be somebody here that wasn't on even our radar before," Salazar said. "This case remains very much an open investigation."
Jaclyn Galbraith, a friend and neighbor of Olsen's, insisted to NBC affiliate WOAI that the mom wouldn't have killed her kids.
"There's no way she would ever do this to her daughters," Galbraith said. "And not to herself."
The bodies were found Thursday by the home's owner, and he's been cooperative with investigators, Salazar said.
The man did not spend the previous night at the house, but he had been "intimately involved" in a relationship the three dead, Salazar added without elaborating.
"As with any homicide investigation we're trying to reconstruct, first and foremost, that snapshot in time of exactly when the time of death was," Salazar said. "We're not there yet."