BARABOO - Twin infants murder defendant David R. Yates will not accept his attorney's advice to make an insanity plea, sending the two on their separate ways Monday and likely meaning a delay in his two-week trial now set for February.

Yates, 46, of Baraboo, appeared for a hearing in Sauk County Circuit Court with his attorney, Mark W. Frank of Madison. He is charged with two counts of first-degree intentional homicide and faces life in prison if convicted.

Sauk County District Attorney Patricia Barrett says Yates battered his 5-week-old children, Tyler and Savannah Yates, to death during the weekend of April 13. A Baraboo police officer found the twins dead in Yates' Lake Street condo after their mother called because he would not answer the door when she came to pick them up. Yates and the mother, Susan Bird-Winbun of Baraboo, were not living together, but she said she left the children with him over the weekend while she worked.

Yates has pleaded not guilty to the charges, according to court records.

During Monday's hearing, Frank said after reviewing the evidence, including video recordings of police interviews with Yates, he believes his client should plead not guilty by reason of mental illness. He said Yates rejected the idea when Frank met with him at the state prison in Waupun, where he is serving time for other convictions.

"Mr. Yates tells me he does not want to enter the plea of not guilty by reason of mental defect or disease," Frank said.

Because the issue of mental illness is so central to making a proper defense in the case, Frank said he believes their disagreement means he must withdraw as Yates' attorney.

During an April call to the Sauk County 911 dispatcher, Winbun said Yates has a panic disorder and had recently blacked out after overdosing on a psychiatric medication. Early in the legal process, another attorney representing Yates expressed concern he was not getting the correct medications while in jail and his mental health issues were being exacerbated. That problem was corrected, the attorney later said.

Judge James Evenson asked Yates if he wanted Frank to withdraw from the case and advised him having to get a new lawyer will delay his trial.

Speaking in a clear voice from his seat at the defense table, Yates said he had written the judge with some complaints about Frank and agreed to have him leave the case. He said he understood his trial could be delayed.

Frank is representing Yates at the request of the Office of the State Public Defender, and Evenson asked him to notify them to appoint a new attorney. The change will likely delay Yates' jury trial, the judge said, so the new defense attorney, Barrett and himself should hold a telephone conference soon to decide the next steps in the case.

Bird-Winbun was in the courtroom along with group of family and friends. She said she had been notified by the county victim-witness office what would be happening and accepts the delay in Yates coming to trial.

"I know what the end results will be, regardless of whatever shenanigans he tries to pull," Bird-Winbun said. "If it takes a few more months to put him in prison for the rest of his life, that's fine."

Bird-Winbun said she is a member of a parents support group and statistics they have looked at show people who murder children get less time in prison than those who murder other adults. She hoped that, when it comes to the time to sentence Yates, the community will support the maximum time in prison as his penalty.

"I'm really confident the state of Wisconsin will not put value on my children's lives for the amount of time they were actually here and he'll get the punishment he deserves," she said.

According to a pathologists' testimony, the twins sustained injuries comparable to being in a car accident in which the vehicle rolls over several times. They sustained severe injuries to the head and chest cause by being struck with something or struck against something.

Because Tyler Yates sustained broken ribs along his spine, the infants may have been held by their chests and struck against something, the pathologist testified. The children were struck fatal blows within 12 to 24 hours of their bodies being found that Sunday evening.

Among the issues to be settled before trial are whether Barrett would be able to use testimony by witnesses who claim to have seen Yates abuse the children or been abused themselves while he was intoxicated. One possible witness allegedly would say Yates attempted to find a paid killer to murder the twins mother before they could be born, according to a document Barrett filed with the court.

Yates is already serving four years of prison and county jail time after being sentenced for parole violations from unrelated drunk driving and domestic abuse convictions.