As Ann Miller Kontz appeared in court Tuesday for the first time after being charged with poisoning her late husband, lawyers predicted her best defense would be to blame a dead man for the crime.

Dressed in a jail-issued blue and white striped jumpsuit, Kontz, 34, appeared in front of a judge on a charge of first-degree murder. Kontz, charged in the death of Raleigh AIDS researcher Eric D. Miller, is being held without bail until a hearing on whether prosecutors have enough evidence to seek the death penalty. That hearing has yet to be scheduled.

The potential target of Kontz's defense in this high-profile killing is Derril H. Willard Jr., Kontz's co-worker and alleged lover, who committed suicide less than two months after Miller's death. Detectives suspect Willard delivered a nonfatal dose of arsenic to Miller by buying and pouring him a beer at a bowling alley in November 2000, the night Miller first became ill.

He was recovering from that dose when someone administered at least one other dose. He died Dec. 2, 2000. The medical examiner blamed his death on "multiple doses" that occurred while he was hospitalized and after his release.

Poisonings are among the hardest cases to prove because they are, almost by definition, stealthy and premeditated crimes. The evidence is almost always circumstantial. No one can testify that they saw the poison administered.

To convict Kontz of murder, Wake prosecutors will have to prove she had means, motive and opportunity. However, Kontz's defense team may attempt to prove those same things about Willard to cast doubt on Kontz's guilt.

Willard's statements

An important factor in Kontz's trial may be statements that Willard made to his attorney before he committed suicide. Those statements, which implicate a third party, have not been made public but might be introduced in Kontz's trial.

After court Tuesday, one of Kontz's defense lawyers, Joseph B. Cheshire V, said, "A lot ... depends on what Mr. Willard said. We certainly will be looking at him carefully."

Johnny Gaskins, a Raleigh defense lawyer, said, "Willard gets the blame for being the real culprit. That's the position I would take." Another lawyer, Karl Knudsen, added, "In this particular case, there is clearly a credible alternative suspect. I assume that would be one of the main avenues of the defense."

When Randy C. Krantz, a Virginia prosecutor who recently handled a poisoning case, heard the basic facts about Miller's death, he agreed that the most likely defense would focus on Willard as the sole killer. Krantz called it the "some other guy did it" defense.

Prosecutors will likely try to show that spikes in e-mail and phone calls between Kontz and Willard around the times of suspected poisonings proved their relationship and the premise that they were working together to kill Miller, Krantz said.

The toxicology and medical testimony about Miller and the timelines will be crucial, Krantz said. "If someone saw him ill, where was the other guy 24 to 48 hours prior to that?"

Krantz, a lawyer for Bedford County, was not successful in his prosecution in Virginia. In June, a registered nurse was acquitted of murder in the death of her multimillionaire husband. Prosecutors alleged that Donna Somerville drugged Hamilton Somerville with prescription painkillers, which she obtained through her volunteer hospice work.

Defense lawyers persuaded a judge of two weaknesses in the case. They argued that evidence of prior exposure to the drugs showed that the victim may have been a voluntary drug user and may have given himself an overdose. And defense experts testified that the cause of death could have been heart failure because the 57-year-old victim suffered from significant heart disease.

"Our poison in that case was a medication, morphine and oxycodone ... the presence of those in the body ... does not mean someone was poisoned," Krantz said. "On the other hand, there is no medicinal purpose for arsenic."

Tough cases

Another Virginia prosecutor, Wade Kizer, in 2002 successfully convicted a woman who poisoned her husband with insulin injections.

"They are tough cases, and juries don't like circumstantial cases," said Kizer, who works for Henrico County. "But that being said, when you have one spouse cheating on the other -- that gives you a pretty good motive. And then you have 'Who else could have done it?' "

Ann Miller spoke to police only briefly on the morning after her husband died.

"If they have any evidence to show that [part of her statement] was untrue, that would help," Krantz said.

Prosecutors will have to show that the person charged is not only a person with a motive but also the only person who had access to the victim when the arsenic was administered.

The Henrico case came down to a combination of factors, Kizer said. But one important one was that when the victim received the insulin, the suspect "was the only person around."

(Staff researcher Denise Jones contributed to this report.)