LOS ANGELES (AP) _ Erik and Lyle Menendez were strong young men ``feeling their oats'' when they shot their parents to death, a prosecutor insisted, ridiculing defense claims that they were helpless victims of their father.

Deputy District Attorney David Conn told jurors in his closing argument, which was to continue today, that a defense portrait of the brothers as weaklings was a fraud.

He argued that they could have left their parents' home if they truly feared being killed. And he contended that Lyle Menendez stayed under his parents' roof because, ``He wanted to be part of his father's life.''

``These were two very competent young men who were feeling their oats,'' Conn told jurors Thursday. ``They felt they had power. There is no true issue of helplessness here.''

He ridiculed Erik Menendez's claim that years of sexual and psychological abuse by his father had destroyed his will and left him with a psychological condition known as ``learned helplessness.''

``There really is no such clinical diagnosis,'' Conn said. ``Erik Menendez was a very competent young man when he wanted to be. He was a championship tennis player. You have to have a sense of self to do that.''

At the end of his third day of summation, Conn drew gasps in the courtroom when he said he still had another full day of talking ahead. The judge said the protracted length of his remarks means he will be limited in his response to the defense argument, now expected next week.

Conn took special aim at Erik Menendez, the only brother who testified at the retrial. The brothers' first trial ended when two separate juries deadlocked. Only one panel is hearing the second trial.

Lyle, 28, and Erik, 25, are charged with murdering their parents, Jose and Kitty Menendez, in their Beverly Hills mansion in 1989.

Conn has asked jurors to convict both brothers of premeditated first-degree murder, conspiracy and special circumstances which could bring them the death penalty.