Sentencing for Nicole Beecroft, who as an Oakdale teenager stabbed her newborn daughter to death, has been delayed until August.

Beecroft, now 24, was scheduled to find out Monday how long she'll be imprisoned, but complications with scheduling an expert defense witness brought the Washington County court proceeding to a halt. Attorneys for both sides twice went to Judge John Hoffman's chambers for consultation before he announced a new sentencing date of Aug. 29.

A California neonaticide expert, Diana Barnes, will submit testimony to support the defense argument that Beecroft deserves less prison time than state sentencing guidelines suggest because of such mitigating factors as her immaturity when she committed the crime.

Barnes was present in the courtroom Monday but left after prosecutor Karin ­McCarthy said that she supported a sentencing delay because she did not become aware until Sunday afternoon that Barnes would testify.

"That late disclosure puts the state, quite frankly, in an unfair position," McCarthy told the judge.

McCarthy and colleague Siv Yurichuk have argued that Beecroft committed her crime with particular cruelty that ­merits a long prison term.

Defense attorney Luke Stellpflug said after the hearing that Barnes, a psychotherapist, wouldn't repeat medical testimony that consumed much of Beecroft's trial last fall, but instead testify about neonaticide, the killing of babies at birth by their mothers.

"This is not about legal defense, this is not about mental illness defense, this is about mitigation," he said.

In 2008, Beecroft was found guilty of premeditated first-degree murder and sentenced to life in prison without parole for killing her baby after she gave birth. Beecroft was 17 when the girl was born.

The Minnesota Supreme Court later granted her a new trial because of allegations of witness tampering in the first trial. Last fall, she was convicted a second time — but on a reduced charge.

Hoffman's finding of second-degree intentional murder meant Beecroft, who will turn 25 in July, someday will be ­eligible for parole.