Cups a clue in family's mystery deaths

• Two parents and three children are found dead in Utah


• There were no signs of trauma, carbon monoxide or air toxins


• Court documents say cups with liquid were by each of the bodies


• Empty bottles of methadone, cold and flu medication found nearby

(CNN) -- Benjamin and Kristi Strack lay dead on their bed. On the floor near them lay the bodies of three of their children, from 11 to 14 years old.

There were no signs of trauma, no indication of toxins in the air. But beside each body there were cups with liquid inside.

5 family members die mysteriously in home

These details come from court documents obtained Thursday by CNN related to the deaths of the five Utah family members, documents that hint at a potentially deadly cocktail including the powerful prescription drug methadone.

Based on this evidence and perhaps more, one of the court documents states that one detective on the case "believes the property and evidence described above is evidence of the crime or crimes of homicide."

Authorities in Springville, Utah, acknowledged Thursday that the recently released information has "re-ignited interest" in the investigation into the Stracks, whose bodies were found September 27.

"The various affidavits written so that officers could fully investigate this tragic event seem to have raised additional questions as to the events that occurred that night," the Utah city's public safety department said in a statement.

Chief among those questions: Who is responsible for the deaths? And why did they die?

There are no firm answers yet, though the court documents made public this week do shed some light on what authorities know and believe.

Documents: Empty bottles of methadone, cold and flu meds

One of them describes how a biological son of Kristi Strack and the son's girlfriend noticed the house was unusually quiet that late September evening and that the master bedroom door had been locked.

Once inside, they and eventually police officers came upon the eerie scene. The parents were in their bed, while the children were around it "covered in bedding up to their necks."

"Officers reported there was a red liquid substance coming from the mouth of Kristi Strack," a police detective wrote in an affidavit for one search warrant. "All of the occupants of the home were non-responsive. Next to each of the victims was a cup/drink with a liquid inside."

Detectives fairly quickly concluded the family members' deaths were due to "poisoning," though exactly what killed them hasn't been officially determined. The Springville public safety department said that might not be known until late November, when the state medical examiner is expected to release autopsies.

The fire department has concluded, however, that "there was no carbon monoxide leak" and "no toxic levels of any kind inside the home," according to an affidavit. Everything in the home was found "to be in good working order."

An affidavit for another search warrant, filed in early October, discussed other evidence found in and around the South Springville duplex.

A black bag put in an outside trash can, for instance, contained "10 opened and empty boxes of nighttime cold and flu medication consistent with generic NyQuil" and "two empty boxes of allergy relief medication consistent with generic Benadryl."

Inside the home, authorities found empty bottles of liquid methadone -- a synthetic narcotic used in the treatment of heroin addiction. The methadone bottles had come from a drug treatment clinic, authorities said.

Methadone contributes to nearly 1 in 3 prescription painkiller deaths in the United States, according to Centers for Disease Control and Prevention findings from 2012.

Police: 'Probable ... deaths were not accidental or natural'

The official documents don't point a finger at any person, in particular, who might be behind the deaths.

Yet authorities -- who continue to investigate, including looking intently at things likely a laptop computer and cell phones found at the Strack's home -- believe that the entire thing was intentional.

The court documents note that it wouldn't be normal for the three children -- son Benson Strack,14; daughter Emery Strack, 12; and son Zion Strack, 11 -- to go to sleep inside their parents' bedroom, since they had their own rooms. And a police officer wrote, in one affidavit, that "with the placement of the bodies, it would appear somebody had to position the bodies after they were deceased."

"It is probable that these death(s) were not accidental or natural in any way," the officer added.

In a statement given Thursday to KSTU, another CNN affiliate, relatives of the Strack family said the release of the documents "was shocking to our family and unfortunately it begins to confirm our suspicions."

The statement did not elaborate, beyond adding: "We are upset about this new information and are struggling as we are forced to relive this horrible tragedy."

CNN's Holly Yan, Joe Sutton and Kate Conerly contributed to this report.