A jury convicted a nurse Monday of killing her husband and placing his body parts in three suitcases she tossed into Chesapeake Bay.

Melanie McGuire, who sobbed as she heard the verdict, was convicted of murder, desecration of a corpse, perjury and a weapons offense.

She was acquitted on two counts of hindering prosecution and falsifying evidence. Authorities charged that she wrote anonymous letters in an attempt to thwart investigators.

During the six-week trial, prosecutors said McGuire, 34, organized William McGuire's 2004 demise using her expertise as a nurse so she could begin a new life with her lover, her boss at a fertility clinic.

The Middlesex County jury was told that two days before her husband was last seen alive, McGuire bought a gun and bullets that matched those found in her husband's body.

The body parts of William McGuire, 39, a computer programmer, were found in matching Kenneth Cole luggage that washed ashore in Virginia in May 2004.

The verdict from the jury of nine women and three men came after about 13 hours of deliberations over four days.

McGuire's attorney, Joseph Tacopina, had argued that the petite nurse was physically incapable of killing her 6-foot-3-inch, 210-pound husband.

Assistant Attorney General Patricia Prezioso told jurors McGuire forged a prescription for a powerful sedative — chloral hydrate — using the name of a patient from her fertility clinic on April 28, 2004, the day her husband disappeared.

During his closing argument, Tacopina also said it also would be impossible to have carried out such a bloody crime in the couple's apartment without neighbors hearing something or without leaving behind physical evidence.

Prezioso told jurors that McGuire most likely had an accomplice, but no one has been named or charged. The prosecutor acknowledged that there were some unanswered questions, but said there was still "overwhelming" evidence to convict the mother of two.

Prosecutors also highlighted Internet searches made from the couple's apartment on topics such as "undetectable poisons" and "ways to kill people."

Tacopina said the defense did not to call McGuire to the stand because they felt the jury had heard the key elements of what she had to say when audio recordings made by two men close to her, who were cooperating with authorities, were played in court.

The recordings were made by Dr. Bradley Miller, with whom she was having the affair, and her good friend, James Finn. During the recordings, McGuire repeatedly says she had nothing to do with her husband's death.

The defense portrayed William McGuire as a man with gambling debts who might have been killed by a creditor.