TAMPA — Shakayla Denson sat in a police car Thursday, after leaving her daughter in the river to drown, and made a comment that may help explain why she did it, court records say.Denson "spontaneously stated (that) now the victim was ‘pure’ and was with her grandmother," according to the records.The previously unreported detail is part of a motion filed Friday by Hillsborough State Attorney Andrew Warren. Warren’s office is asking a judge to order Denson, 26, held in custody while her murder case proceeds, saying she poses a threat to the community. RELATED: Witnesses: Girl struggled, screamed as mother dragged her into Hillsborough River Police divers recovered the body of Je’Hyrah Daniels, 4, from the Hillsborough River near the Columbus Drive bridge and arrested her mother nearby. Child protective workers had received a tip about six weeks earlier that Denson was overwhelmed raising her autistic daughter.In another development, the Tampa Police Department on Monday released two calls made to 911 about the incident.In one call, a man says two women cleaning his father’s house on Rome Avenue phoned him to say they saw a woman "throwing a child in the river."More coverage: Listen to the 911 calls from two witnessesThe man’s name is redacted from the call but he spoke to the Tampa Bay Times on Friday. Ernest Carrera, 50, called 911 about 4 p.m. after speaking to the house cleaners. He translated their account to the 911 operator. "If I saw this kid I’d jump in and get him but I can’t find him in the river," Carrera says in the call, a growing urgency in his voice. "Just bring somebody to the location. We’re out here looking for the kid." Carrera notes that there are shoes near the Nissan Altima the woman was driving.The operator asks if what the house cleaners saw might have been a doll."She says it was a live kid," Carrera answers a couple of moments later, translating.In Spanish, one of the women can be heard to say on the call, "She took off a green hat and took the little boy that she brought to the middle of the river where she left it and started screaming ... and I see the little arms, I could see them moving."Later, she adds, "the child is drowning, the child is drowning, and I could not do anything. I saw how the child sank."Police say Denson stole a car from an auto repair lot on North 40th Street Thursday, drove her daughter to the river and dragged her into the water. Witnesses said Je’Hyrah was struggling with her mother and screaming, and at one point, Denson began to scream, too.Clutching the girl to her chest, Denson reached shoulder-deep water then let her daughter go, police said. The little girl floated away and Denson headed back to shore, police said.She was charged later that day with first-degree murder, aggravated child abuse and grand theft auto.On Friday, police Chief Brian Dugan said investigators were still trying to figure out what led Denson to leave her daughter in the river. Her immediate family members have said little publicly, and a cousin Friday said he is seeking answers.A friend who had recently seen Denson said these weren’t the acts of the woman and loving mother he had known.Child-protection workers visited Denson on June 20 to investigate the tip that she was overwhelmed and not properly supervising her daughter. RELATED: Child protective investigation found no concerns about 4-year-old days before her death in Hillsborough RiverBut an investigator found that Je’Hyrah Daniels, though non-verbal, seemed happy and healthy. Denson’s sister and two neighbors endorsed her parenting. The Sheriff’s Office closed the investigation on July 30, concluding that there was no evidence of maltreatment, abuse or neglect. ‘She was not an evil person,’ friend says of woman who left child to die in river The report is under review by the state Department of Children and Families, a standard practice whenever a child dies within five years of an investigation.Myriam Silva-Warren of CENTRO, a Times sister publication, contributed to this report. Contact Tony Marrero at [email protected] or (813) 226-3374. Follow @tmarrerotimes.