They were brought back to Poplar Bluff, where officers interviewed them, Deputy Chief Jeff Rolland said.
"To our amazement and disappointment, they were bonded out before we could even transport them" to the Butler County jail, police chief Danny Whiteley said. They were released after posting $50,000 cash bonds.
The allegations involved two young children being injured and medical treatment being withheld for several days, police Lt. David Sutton said in his probable cause statement.
Specifically, he said, the 23 month old had been "burned, and Sterling Marshall struck [the 3 year old] in the face."
When authorities arrived at the home, Sutton said, patrolman James Henry knocked repeatedly on the front door, but received no response.
"[He] heard children crying in the residence, and made entry through an unsecured door at the rear of the residence," Sutton explained. "Inside, Officer Henry found Sterling Marshall hiding in a bedroom and found Donnisha Nelson hiding in the bathroom with the children."
Examination of the children, Sutton said, confirmed they were injured in a "manner consistent" with the report and that "necessary medical attention had been withheld."
The children, according to earlier reports, were taken to Poplar Bluff Regional Medical Center, where they were treated and released.
"According to medical staff, [the younger toddler] had serious [second- and third-degree] burns on several locations on his body, and [the 3 year old] has suffered a broken jaw," Sutton said.
Upon evaluation of the 23 month old, Rolland said, medical personnel found 53 individual burn marks in "different stages of healing. Twenty-one were on his chest and back.
"There were numerous on each leg, as well as each arm. The child also had numerous burns on the neck and face, to include his ears and lips."
During an initial interview with Nelson, she reportedly outlined an accidental cause for the injuries.
"The burns are not consistent with the story the mother had relayed to us," Rolland said.
"We can think of no scenario that comes close to matching her rendition of the events to create the enormous amount of injuries to the child," Whiteley said.
According to Sutton, Lowerstine Nelson-Green told officers during an interview that prior to the child abuse hot line call, she had approached her sister and had offered to take the children for medical treatment.
"Donnisha Nelson refused, saying that she feared she would be accused of abusing the children," Sutton said.
Under the direction of Family Services, the boys reportedly were removed from their home last week and placed with a relative, who is being monitored by Family Services officials.
A juvenile hearing, Rolland said, was held Tuesday, during which Nelson requested a chance to hire an attorney. For now the children, he said, will remain in the custody of family members under continued supervision.
"We find it incomprehensible that a parent would allow this type of injuries to occur to their children and then not seek immediate medical help," Rolland said. "It is our opinion that the two children in question should never be given back to these individuals.
"They have demonstrated through their actions and inaction that they do not have the safety and welfare of these helpless children first and foremost in their minds."
Nelson and Marshall are to appear at 9 a.m. Jan. 20 before Associate Circuit Judge John Bloodworth for arraignment on the charges.
"The investigation is continuing," Rolland said. "We are conducting follow-up interviews, which continue to discredit the scenario the mother has presented to us to explain the injuries to both children."