Dan Rozek

The father of three slain Naperville children is scheduled to be the first witness today when DuPage County prosecutors open their case against his ex-wife, Marilyn Lemak.

Dr. David Lemak is expected to testify about his ex-wife’s moods and actions in the hours and days leading up to the March 4, 1999, killings, which occurred during the Lemaks’ bitter divorce proceedings.

Before testimony begins, attorneys for the prosecution and defense must pick two last alternates for the jury that will decide whether Marilyn Lemak is guilty of first-degree murder. Jury selection is expected to be completed this morning. A six-man, six woman jury- along with two alternates- already is in place.

The 44-year-old former surgical nurse is raising an insanity defense to charges she drugged and suffocated the estranged couple’s three young children.

David Lemak has spoken in public just twice in the 2 ½ years since the deaths of 7-year-old Nicholas, 6-year-old Emily and 3-year-old Thomas. He eulogized the children at their funeral a week after the killings, and he testified at a six-minute court hearing in October 1999 that finalized his divorce. He didn’t speak directly either time about the killings or about his ex-wife’s behavior leading up to the deaths, which rocked the quiet suburb where they lived.

DuPage County State’s Attorney Joseph Birkett is prosecuting the case. He plans to argue that Marilyn Lemak killed the children to spite her estranged husband after learning he’d begun dating another woman.

Defense attorney John Donahue has said he will argue that Lemak, dogged by a depression that only worsened as her divorce dragged on, was insane at the time of the killings.

It’s a difficult defense, seldom tried in Illinois and rarely successful. Even lawyers for serial killer John Wayne Gacy couldn’t get a jury to find him insane after he ass arrested in 1978 on charges he murdered 33 young men and boys.

“With so many bodies, so many deaths, it would be difficult to imagine a jury would not find him insane,” recalled one of Gacy’s attorneys, Sam Amirante, who is now a Cook County judge. Prosecutors successfully argued during the 1980 trial that Gacy was “evil, not insane,” Amirante said.

Changes in state law in Illinois, as well as in other states, since 1984 have made it even tougher to win acquittal on the basis of insanity. Those changes followed John Hinckley’s acquittal on insanity grounds following his 1981 assassination attempt on President Ronald Reagan. Defendants mounting an insanity defense in Illinois now must prove by “clear and convincing evidence” their insanity. Before 1984, it was prosecutors who had the burden to prove defendants were sane.

Also, legislators tightened the law by eliminating one of the two arguments defense attorneys could use on their clients’ behalf. Under the current law, Donahue can argue only that a mental disease or defect left Lemak unable to appreciate or understand that her actions toward her children were criminal.

“The insanity defense is virtually dead these day,” said DePaul University law professor Leonard Cavise.

Northwestern University law professor Paul Robinson said he likes that defendants have the burden of proving they were insane at the time they committed a crime/ “It’s reasonable they should have to prove it,” said Robinson, a former federal prosecutor.

Donahue and his defense team likely will try to show that Lemak showed signs of irrational behavior both before and after the killing to bolster claims she was insane when the children were killed, defense attorneys not connected with the case say.

“That someone just snapped is going to be tough to prove,” said veteran trial attorney David Camic of Aurora. “They’ll want to show she was disturbed and had signs of it beforehand.”

Prosecutors are expected to argue that the killings were premeditated and that Lemak had a clear motive- “revenge, rather than mental illness,” is how Amirante put it.

“Anything that shows premeditation, that she thought about (killing the children), cuts in the state’s favor,” said Terry Ekl, a criminal defense attorney who practices in DuPage County.

If the jury ends up agreeing that Lemak was insane at the time of the killings, she would be committed to the state’s Mental health Department. The time that a person acquitted because of insanity spends in a locked treatment center can range from a couple of years to life, with the average stint being about 5.3 years said Dr. Ron Simmone, chief of adult forensic programs for the state mental health agency.