Crime Texas Mom 'Heartbroken' After Missing Boy's Body Is Found, Blames Ex-Husband for Tragedy Police arrested the husband's girlfriend on a charge of tampering with evidence after finding her in a motel room Tuesday with a body believed to be that of 6-year-old Samuel Olson By Jeff Truesdell Published on June 3, 2021 03:23 PM Share Tweet Pin Email Sarah Olson with her son, Samuel Olson. Photo: Courtesy Sarah Olson A Texas mother who says she hadn't seen her missing 6-year-old in more than a year is confronting a devastating loss after authorities said they recovered a child's body they believe to be her son. "I'm heartbroken, but I believe that body is my baby," the mother, Sarah Olson, said in comments shared with PEOPLE by her attorney. She also blamed the child's father --- her ex-husband, Dalton Olson -- after police said they found Dalton's girlfriend, Theresa Balboa, in a Jasper, Tex., motel room with the child's body late Tuesday. Balboa was arrested on a charge of tampering with evidence, after claiming that the boy had been taken from her Houston apartment five days earlier. Body is Found at Texas Motel in Search for Missing 6-Year-Old Boy -- and Dad's Girlfriend is Arrested Dalton Olson has not been charged, but is continuing to face questions from police, Houston's Assistant Police Chief Heather Morris said Wednesday at a news conference. Samuel Olson. Courtesy Sarah Olson Sarah Olson with her son, Samuel Olson. Courtesy Sarah Olson "If Samuel is deceased, [his] death is on Theresa and Dalton," said Samuel's mother. RELATED VIDEO: Sarah Olson's Attorney Marco González Shares Her Response to Body's Discovery Neither a call nor a text message sent to a phone for Dalton by PEOPLE were immediately returned. No information on an attorney or plea for Balboa, who was being held in the Jasper jail after her arrest, was immediately available. Sarah and Dalton Olson are divorced but were engaged in a custody dispute after Sarah alleges Dalton failed to return the boy to her after a January 2020 weekend visit with his father, González said at a news conference Tuesday. Sarah had primary custody of Samuel, but the father had been awarded visitation rights. Samuel Olson. Courtesy Sarah Olson Sarah last saw her son around the time he turned 5 over Memorial Day weekend in 2020, Andrea Gomez, a spokesman for González, tells PEOPLE. Last Thursday, police responded to Balboa's Houston apartment in response to a missing person's call. Balboa allegedly told officers she'd seen Sarah with an unknown officer at 7 a.m. that morning outside of the apartment, and claimed the officer told her she would go to jail if she did not return the boy to his mother, police said at a news conference Wednesday. Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases. According to police, Balboa said the officer and the boy's mother then left in separate vehicles. After the boy's father heard this story from Balboa, he contacted Sarah, who said she did not have the missing child, police said. Investigators later determined that Sarah was at her own residence that entire morning — and they discovered other alleged "inconsistencies" in Balboa's statements, said Morris. After carrying out search warrants and then towing a vehicle from the apartment complex where Balboa was living, Houston police learned of an anonymous tip to CrimeStoppers that led officers to the Jasper motel 100 miles away. Samuel Olson. Houston Police/Twitter "At this time we believe the child to be Samuel, but we cannot confirm that it is him until the medical examiner makes that determination" Morris said. Police earlier revealed that the boy may have gone missing as early as April 30, when he was last seen by staff members at his school. Sarah's efforts over the past several months to reclaim her son and deliver legal paperwork to the boy's father that would enforce her primary custody were stymied by court delays caused by the pandemic, as well as Dalton Olson's apparent jumping among residences, said Gomez, the spokesman for Sarah's attorney. Police also confirmed that Samuel had been enrolled in at least two different schools during that time. "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."