PROVO — Prosecutors and defense attorneys were tight-lipped last week about a sudden change in schedule for the case in which a Utah County couple is accused of giving their adopted daughter so much water that she died.

But a source close to the case has told the Deseret News that prosecutors are planning to drop current charges against the Springville couple and re-file different counts.

Richard and Jennete Killpack are charged in the death of their adopted daughter, 4-year-old Cassandra Killpack. The couple faces second-degree felony child abuse homicide and third-degree child abuse.

But the couple's defense attorneys question the appropriate application of the child-abuse homicide statute in the case. And that may prompt prosecutors to take a different legal route.

In a 40-page memorandum filed in 4th District Court, defense attorney Phil Danielson argued that the child-abuse homicide statute, which is a relatively new law, is vague in its use of the term "reckless" in regards to conduct.

At question is whether the word "reckless" pertains to the child abuse aspect of the statute or the homicide part of the law.

The outcome of the legal wrangle could make the state's burden of proof to a jury much easier to prove, Danielson said.

"The express reference must refer to the death of the child," Danielson wrote in his memorandum. "The state must also show that the conduct was not justifiable" by a reasonable person.

But prosecutors say the reckless conduct applies to the child abuse aspect, making it a lighter burden of proof for a jury to convict because they would not have to find that the girl's death was intentional.

A preliminary hearing was put on hold May 8 after a legal debate arose about the wording of the statute. Judge James Taylor ordered both sides to submit their arguments in writing in anticipation of a hearing Thursday. But the hearing was suddenly postponed until Wednesday.

Deputy Utah County Attorney Sherry Ragan said the state had not submitted its argument on the child-abuse homicide issue. When asked about the possibility of amending the criminal charges, Ragan said she could not comment.

Danielson said a court-imposed gag order precluded him from commenting on the case.

A source involved in the case who did not want to be identified told the Deseret News that the current charges may be dropped and replaced with different counts, which were unknown to the source. How this might impact the ongoing preliminary hearing, which is in its second day, attorneys could not say.

Testimony from emergency-medical workers show that Richard Killpack placed a 911 call after the girl collapsed and lost consciousness on June 9. When a Springville EMT crew arrived, they testified finding pink foam coming from the girl's mouth and that her belly was distended. One EMT testified that she could not stop the pink foam from coming out of the girl's mouth long enough to get a clear airway.

A doctor at Primary Children's Medical Center testified the girl's brain had swelled and that extensive lung damage had occurred.

Both the doctor and the state medical examiner testified that Cassandra Killpack died of having ingested an estimated 2.5 liters of water, forcing her blood sodium levels to drop and her brain to swell. Experts say the girl literally drowned in her own bodily fluids.

Prosecutors allege that the couple bound the girl's hands behind her back and forced water down her throat as punishment for taking a sibling's cup. An autopsy showed bruising and a cut around the girl's mouth.

Attorneys in the case say many questions will be answered during the hearing next Wednesday.