LOS ANGELES (AP) _ In an often-theatrical argument on behalf of accused murderer Erik Menendez, a defense attorney suggested that his mother kept a secret of incest in order to save her marriage.

Erik, 23, and Lyle Menendez, 25, are charged with the murder of Jose and Kitty Menendez, who died in a blaze of shotgun fire in their Beverly Hills mansion on Aug. 20, 1989.

In her closing argument Tuesday, defense lawyer Leslie Abramson depicted entertainment executive Jose Menendez as a mad scientist who bred his sons on fear, torturing them like laboratory animals in a ''little human experiment.''

Prosecutors belittle the claim of sexual abuse as a defense ploy to win the sympathy of jurors.

Because the crime was an ambush allegedly committed to control a $14 million family fortune, the defendants could face the death penalty. The defense wants manslaughter verdicts, which could set the brothers free in a few years.

Abramson theorized that Mrs. Menendez saved her marriage, her money and her place in society by agreeing in 1986 to conceal her husband's molestation of Erik.

''I think Mrs. Menendez made her deal with the devil,'' she said. ''She gets to harangue him forever and she keeps the secret.''

Abramson also noted that a coroner's report shows Lyle, not Erik, fired the final shots that killed each parent.

A separate jury for Lyle began deliberating last week.

Jurors were expected to get Erik's case today after Abramson finishes her closing argument.