Suspected Gilgo Beach Serial Killer's DNA Matches Key Pizza Evidence

The suspected Gilgo Beach serial killer is almost certainly the one authorities have been seeking for years -- this according to prosecutors, who now say the proof is in the pizza.

Rex Heuermann appeared in court Wednesday for a status hearing ... and prosecutors announced a couple of big developments in the case -- including their claim Heuermann's recently collected DNA (via cheek swab) does in fact match the DNA profile they found on a discarded pizza crust ... which was the key to cracking this whole thing.

As a refresher ... cops went through Heuermann's trash in search of DNA and say they found some on the pizza which they later concluded matched DNA from a hair follicle discovered in a burlap sack that contained remains from one of the 4 victims.

Now, in the wake of further testing ... the D.A.'s office is saying there's no doubt the DNA they found on the pizza belongs to Heuermann. Essentially, they're declaring they have their man.

While prosecutors insist the pizza DNA matches ... Heuermann's defense team made sure to emphasize in court the hair follicle DNA isn't quite so clear ... arguing that the hair could belong to other people, even though law enforcement has alleged 99.96% of the North American population can safely be excluded as a match.

Another nugget of info that surfaced during Wednesday's appearance ... Heuermann told the judge he'd been going over evidence in his jail cell -- explaining he'd been dedicating 2-3 hours a day, on average, to review materials provided by the prosecution.

Prosecutors say they've forked over at least 10 terabytes worth of info to Heuermann and his legal team -- so there's a lot to pore over, and there may be more to come.