When authorities discovered the entire Harless family dead in the back of an SUV last month, they theorized that the 38-year-old father was solely responsible the deaths.
Now, Lt. Jesse Salame said Harless had help from his wife, 36-year-old Sheryll Ann, and conspired together in the murder-suicide.
A medical examiner confirmed that the family-of-five died from carbon monoxide poisoning.
Lt. Salame admitted to the San Antonio Express-News that an official motive has not been determined, but listed several possible catalysts that could have triggered the deaths.
'A combination and life stress that was exacerbated by some mental health issues, and the stress that is not uncommon with having children with special needs as well,' were key factors in the apparent murder-suicide.
Authorities identified the children as Esteban Lorenzo Harless, 4; Penelope Arcadia Harless, 3; Avielle Magdalena Harless, 1, and 11-month-old Apollo Harless.
It's unclear which of the four children may have had special needs.
Esquibel Harless was a US Army soldier assigned to the 470th Military Intelligence Brigade at Joint Base San Antonio and had moved to the neighborhood in January from Washington State.
Neighbors told Fox San Antonio the family were new to the area but they never saw anything 'out of the ordinary'.
On June 4, police officers responded to a gated subdivision where the Harless family had a two-story home.
San Antonio Police Chief William McManus said the smell of carbon dioxide was so strong when officers arrived that it 'kind of blew everybody back out the door.'
He said police had gone to the house for a welfare check requested by the husband's employer, who had been unable to reach him.
'They were OK yesterday because he checked in with his work,' McManus said. 'So it happened sometime overnight.'
McManus said on the front door of the home was a 'cryptic note' with military jargon.
A member of the military translated it to: 'Bodies or people inside, do not enter. The animals are in the freezer.'
The chief said the note also hinted at booby traps.
'Based on the note that we received, we were very cautious about going in, and we were trying to find out what was in there before we made entry,' the chief said.
When they entered, the cops were overcome by a heavy, noxious odor which turned out to be carbon monoxide.
Police said they found some explosives after they entered, but they were not rigged, Ken 5 reports.
The family was found in the back seat of a SUV inside the family's garage. Two pet cats were also found dead in the front seat.
'It's the whole picture. The adults, the children, the pets,' McManus said. 'Saying it's not pretty - there's no words to describe that.'
At the time, McManus said there was evidence that 'it was not an accident' and he did not suggest that anyone outside the family was involved.
🚨This is the home where a family of 6 was found dead
— Emily Olson (@EmilyOlsonTV) June 5, 2020
🚨They were in an SUV in their garage
🚔Officers overwhelmed by heavy fumes
✉️A note said there were bodies inside and not to enter
🎥We’re LIVE on @KABBFOX29 and @News4SA w/ the details
📸: @ulysses_romero pic.twitter.com/YJVA3inZxk
