Gascón told a jam-packed room filled with reporters and cameras ... he will go to court Friday to file for the resentencing of Erik and Lyle. Based on their ages at the time of the crimes, he will recommend they should be eligible for parole immediately.

This means if a judge signs off Friday or later, a parole board will decide if the brothers should go free.

Gascón said he believes resentencing is appropriate because Erik and Lyle don't represent a threat that they'll commit another crime. He notes Erik was 18 and Lyle was 21 when they killed their parents, and underscored they were very young, although he says he is not excusing their behavior.

Gascón says despite their life without parole sentences, they have been rehabilitated. He says they have been model citizens behind bars and have earned his decision. He says they have paid their debt to society after 35 years.

Gascón referenced a recent documentary that spiked public interest in the case, and he said the interest made him decide to accelerate his decision. A hearing had been set for late November. That's interesting, because Gascon is up for reelection November 5. When asked directly about that factor during Thursday's press conference, he declined to comment. However, it's interesting to note he did not issue a denial.

Various Menendez relatives were among the crowd as Gascón made his announcement.

Gascón said there was an internal conflict in the D.A.'s office over his decision ... some felt the brothers were not molested and should stay in prison.

Thursday's news conference comes after Gascón announced earlier this month he was reevaluating the case after new evidence was presented -- a letter Erik wrote to his cousin Andy Cano months before the murders, in which he says his father José was still molesting him.

The case also received another look after Roy Rosselló -- a former member of the band Menudo -- claimed José had sexually abused him.

Rosselló's claims line up with what Erik and Lyle said about their father during the first trial. That trial ended in a hung jury, and a judge prohibited them from presenting the claims in their retrial.

In 1996, both brothers were sentenced to life in prison without parole for the 1989 shotgun murders of their parents.

Currently, the brothers' next court date is November 26 ... just 2 days before Thanksgiving -- which their family says they hope the duo can attend.

More than 20 members of their family -- from both their mother's and father's sides -- appeared at a press conference just last week advocating for their release.

On the other hand, a reporter who covered the first trial told TMZ he thinks the brothers should remain in prison for life.