Math Errors Undercut Case Against Nurse

Botched math has forced prosecutors to back away from key evidence in the trial of a nurse accused of murdering four patients at a veterans hospital, court papers revealed Friday.

The papers were released just hours after testimony about a possible confession by the nurse, Kristen Gilbert, to her one-time boyfriend.

Defense attorney Harry Miles told the U.S. District Court judge the case should be dismissed in view of the mathematical mistakes. He was expected to file a written motion for dismissal next week.

Gilbert, 33, of Setauket, N.Y., is accused of killing four patients and attempting to kill three others at a Veterans Affairs hospital in Northampton in 1995 and 1996. Her trial began in November.

The government has said she gave the patients adrenaline to make their hearts race out of control. Defense lawyers say the patients died of natural causes or of drugs out of Gilbert’s control.

The government had said it would prove adrenaline poisoning from analysis of tissue samples by Dr. Frederic Rieders at National Medical Services in Willow Grove, Pa. In its opening statement, the government put these calculations at the core of its scientific case against Gilbert.

But government prosecutors notified Gilbert’s lawyer about the math mistakes in a Dec. 19 letter. The government said it will likely dump the scientific evidence for adrenaline poisoning, according to defense papers.

Defense lawyers say they believe the government now intends to make its case without scientific proof of a specific poison.

Assistant U.S. Attorney William Welch II declined to comment outside of court Friday, citing a court-imposed gag order. Rieders did not return a message seeking comment.

The disclosures capped a day packed with testimony that could otherwise bolster the government case. Earlier in the day, a hospital security guard who had an affair with Gilbert testified she made an apparent confession to him.

James Perrault said she phoned him from a hospital psychiatric unit, where she was being treated in July 1996. He said she told him, “I did it! I did it! I injected those guys with a certain drug.”

But later, Gilbert told him she was only trying to make him angry, Perrault said. The two were breaking up at the time.

Perrault also testified that Gilbert used to ogle his muscles and grind her hips into him during medical emergencies. Prosecutors have suggested that she provoked emergencies in an attempt to excite Perrault with her take-charge attitude and flirting.

Gilbert could get the death penalty even though Massachusetts banned capital punishment in 1984. The case is being tried in federal court because the alleged crimes took place on federal property.