Theresa Balboa has been arrested on a charge of tampering with evidence

samuel olson
Samuel Olson
| Credit: Houston Police/Twitter

Samuel Olson, the 5-year-old Houston boy who was reported missing on May 27, may have died weeks before authorities were notified of his disappearance, according to new court documents.

Authorities said in charging documents that Theresa Balboa, the girlfriend of Samuel's biological father, allegedly called her roommate on May 10 to tell him that the boy had died, KTRK-TV, The Houston Chronicle and KPRC-TV report.

During the police investigation into Samuel's disappearance, the roommate reportedly told investigators that he returned home after the phone call and found the child — whose 6th birthday was on Saturday — bruised and unresponsive on the bed.

The roommate allegedly said he and Balboa moved Samuel's body to a bathtub and left him there for two days, according to court documents cited by KPRC-TV, before wrapping the boy up in a plastic sheet and placing him in a tote to take to a storage unit in Webster, Texas.

On Monday, amid the search for Samuel, another male friend received a call from Balboa asking for help, authorities said in court documents obtained by KTRK-TV.

The friend allegedly told investigators that he picked Balboa up and the two drove to the storage unit, where they retrieved a plastic container with a foul odor and transported it to a motel room in Jasper, Texas, according to KTRK-TV.

Police were directed to the motel after receiving an anonymous tip from CrimeStoppers.

In a news conference on Wednesday, Houston's Assistant Police Chief Heather Morris said that authorities believe the body found at the motel "to be Samuel, but we cannot confirm that it is him until the medical examiner makes that determination."

Balboa, who previously claimed that Samuel had been taken from her Houston apartment, was arrested on a charge of tampering with evidence after she was also found at the motel, Morris said.

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Samuel's father, Dalton Olson, has not been charged, but is continuing to face questions from police, according to Morris. Police previously said that Samuel's biological parents have shared custody of the child.

On Thursday, Samuel's mother, Sarah Olson, said in comments shared with PEOPLE by her attorney, "I'm heartbroken, but I believe that body is my baby."

"All I want is justice for Samuel, my baby," Sarah said, according to her attorney. "I do not want people to forget Samuel's name."

Neither previous call or text message sent to a phone for Dalton by PEOPLE were returned. No information on an attorney or plea for Balboa, who was being held in the Jasper jail after her arrest, was immediately available.