An Arlington jury began deliberations yesterday in the retrial of a Arlington man whose convictions on rape, robbery and malicious wounding charges were overturned because his lawyer was confused about the time the crimes allegedly occurred.

The Circuit Court jury in the retrial deliberated 2 1/2 hours yesterday and is scheduled to resume this morning.

D'Alesandro Barber, 27, was found guilty by a Circuit Court jury last December of raping, robbing and cutting a woman after breaking into her first-floor apartment last July. The jury recommended a 45-year sentence.

Barber's attorney in the first trial, Edward C. Farstad, had acknowledged in court that he went to trial believing the attack occurred at night on July 11, 1982, and told jurors his client did not have "a red-hot alibi." The incident actually is alleged to have taken place around 2:45 a.m. that day.

Barber's conviction was overturned last April when the trial judge ruled that Barber did not have "effective assistance of counsel" and ordered the new trial.

This week, two defense witnesses testified that Barber was with them in Washington at the time of the attack. Richard C. Shadyac, Barber's new attorney, based his defense on the testimony of those witnesses.

The victim, a 22-year-old woman who said she was so traumatized by the event that she did not remember she was raped until three months later, identified Barber in court Monday. During the trial, Shadyac challenged the identification given by the victim, a woman who he said "doesn't even remember she was raped." Shadyac said the prosecution had "set up" the defendant by showing the victim pictures of Barber.

State Assistant Attorney Helen Fahey based the prosecution's case on the identification given by the victim, physical evidence that Fahey said links Barber to the scene and discrepancies in the testimony of the defendant and his witnesses.

During two hours of questioning on the stand Monday, the woman said her attacker had a small beard. Yesterday, Barber, a sister and a cousin testified he has never had a beard or goatee.

The trial's final witness was a police officer who said Barber had a goatee three weeks prior to the attack, when Barber was questioned during a domestic disturbance. The officer did not testify at the first trial.

In closing arguments, Fahey told the jurors that Barber's witnesses "do not believe or do not want to believe" he was the attacker and "are willing to alter the facts at least a little bit."