SALT LAKE CITY (AP) — Relatives of five Utah family members found dead in a locked bedroom last month suspected the deaths weren't accidental, and revelations that poison likely killed them confirmed their suspicions, according to a statement released Thursday.

Jacob Strack said his family is struggling after learning from search warrants Wednesday that police found cups with a red liquid inside next to each of the bodies, some of which appeared to have been positioned after death. Empty packages of methadone and cold medicine were in the family's trash.

Benjamin and Kristi Strack were found Sept. 27 in a bed with three of their children, ages 11 to 14, lying around them tucked into bedding up to their necks. Kristi Strack had a red liquid coming out of her mouth.

The family was shocked and upset by the information, but it unfortunately confirmed their fears, according to a statement from Jacob Strack, who is Benjamin Strack's brother and is acting as a family spokesman. He declined to elaborate, saying the relatives are working with the National Alliance on Mental Illness to release more information later.

The bodies were found by the couple's older son and Kristi Strack's mother, who said she couldn't believe "she" would do this to the kids but wouldn't elaborate, according to the search warrants.

Court records show the couple had a history of legal and financial problems, and had gone through court-ordered drug treatment several years ago. The methadone found in the home had been dispensed by a drug treatment clinic, the search warrants said. Methadone is a prescription drug used for decades to treat drug addiction, but is increasing prescribed for pain, according to the Centers for Disease Control and Prevention.

But the Stracks' troubles appeared to be behind them, said Alex Short, owner at AK Masonry, a bricklaying company where Benjamin Strack worked.

"When he came over, he was kind of at the tail end of all those problems," said Short, who employed Benjamin Strack for about seven years on-and-off. He was at times a solid employee, but would occasionally stop showing up for work for periods of time, explaining his absences by saying he was doing things for his wife, Short said Thursday. He hadn't been at work for more than a week when he died.

Police in Springville are awaiting toxicology results next month that could pinpoint an exact cause of death, and speculating before then would be unprofessional, said Lt. David Caron in a statement Thursday.

Investigators found empty methadone bottles, 10 empty boxes of nighttime cold medicine and two boxes of allergy medicine in the family's garbage, along with a red liquid substance in Pepsi cups. They also found a pitcher of red juice, a purple bucket with yellow liquid, a bag of marijuana and other medications, including sleeping pills.

Methadone can be lethal when taken in excess. Thousands of people die each year from methadone overdoses, according to the CDC.

The couple also has an older son, whose girlfriend also lived with the family. She was the last to see Kristi Strack alive at 6 a.m. The girlfriend went back to sleep after talking with her, and the house was quiet when the couple left that afternoon.

When the older son and his girlfriend returned at 7 p.m. and found it still quiet even though all the cars were in the driveway, they knocked on the master bedroom door. After no one answered, the couple called Kristi Strack's mother and her friend, who helped them force it open.

The five were identified as Benjamin Strack, 37, his wife, Kristi, 36, and three of their children: Benson, 14, Emery, 12, and Zion, 11.

Springville is a city of about 30,000 near Provo, about 45 miles south of Salt Lake City.