SAN DIEGO - An attorney representing a 33-year-old mother of four plans to file an appeal following her conviction for first-degree murder in the poison death of her 23-year-old Marine husband, whose $250,000 life insurance policy she used in part to pay for breast implants.

Cynthia Sommer, 33, faces life in prison without parole when she is sentenced March 23. The verdict was handed down yesterday, the third day of deliberations by a seven-woman, five-man jury.

In addition to the murder charge, Cynthia Sommer was convicted of the special circumstance allegations of murder by poison and murder for financial gain.

Sgt. Todd Sommer's death on Feb. 18, 2002, at Marine Corps Air Station Miramar was originally thought to have been from natural causes. But a test in 2003 for heavy metals showed arsenic levels more than 1,000 times the normal level in his liver and 250 times above normal in his kidneys.

Prosecutor Laura Gunn said the defendant was the only person who could have poisoned her husband and suggested Cynthia Sommer was easily able to get arsenic - possibly in the bait from retail ant traps - and give her husband a large amount of it.

Cynthia Sommer's attorney, Robert Udell, questioned the standard operating procedures of the military laboratory that conducted the metals test.

The defendant made four inquiries about money in the first five hours after her husband died, Gunn said. Then, over the ensuing weeks, she paid $5,400 for breast implants, had sex with three male Marines and a woman, hosted loud parties at her house and participated in a wet T-shirt and thong contest in Tijuana, the prosecutor said.

Udell said an appeal was planned on two grounds: the legal sufficiency of the evidence and the fact that the judge allowed prosecutors to put on evidence of the defendant's sexual conduct with multiple partners after her husband's death.