Prosecutors could compare any new information they obtained from the Kalpoe wiretaps to evidence and statements obtained back in 2005, but the nature of any new evidence and its legal value remain speculative.
Given the intentionally vague and thoroughly contradictory manner in which each side is characterizing the new information to the press, it's nearly impossible to assess the impact it could have on the investigation.
But along the way, there have been tantalizing hints of some form of culpability among the trio.
According to an evidence transcript reviewed by ABC News, Van der Sloot apparently told Deepak Kalpoe, in a conversation in a car that was bugged by police, "You know what happened to that girl," and later, "If you have done something bad to the girl, we will see."
Lawyers on both sides of the case have lately displayed an almost aggressive confidence in their respective analyses of the evidence to date.
Ronald Wix, who represents the Kalpoe family, told ABC News this week that the prosecutors' so-called new evidence essentially centers on a reexamination of old evidence from 2005 that was simply reviewed by a new team of investigators, using more current technology.
"What they did is, they took a lot of old evidence and presented it as new evidence," Wix said. "And how they argued that is, that, 'well, now we have state-of-the-art equipment that we didn't have back then to analyze this evidence, and now we're looking at the evidence differently, and that constitutes new evidence.' It's not."
Wix insisted that "99 percent is actually old stuff, [and] that 1 percent new is not enough to give these guys a parking ticket."
Prosecutor Hans Mos disputes that contention.
"We found these new leads and reinvestigated the old file we had,'' he said. "Then, you have to make a decision. Do you just want to cover up, like some people in America think we do? And say, 'OK, everything is nice and quiet in Aruba,' and we don't do anything anymore? That was not our choice. We wanted to solve this case."
Prosecutors have said they believe they can prove that Holloway is dead, but have not disclosed how.
Today's hearings, closed to the public, will address two issues — whether the Kalpoe brothers, who currently each have their own attorney, can be represented together, and whether Van der Sloot's incarceration conditions are overly restrictive, as his lawyers claim. Neither issue is expected to be ruled on until at least Friday, according to prosecutors.
Unlike previous detentions of the trio, each of the men is being held in separate police facilities around the island.
Defense lawyers have argued in court, and declared publicly, that the "new evidence" used to rearrest the men is legally thin. But a judge in the case ruled this week that the evidence was sufficient to rearrest and detain the three men. The Kalpoe brothers will be detained at least until Friday. Van der Sloot, arrested in the Netherlands and transported to Aruba earlier this week, will be held until at least Dec. 7.
None have been officially charged with a crime, but they were arrested on suspicion of voluntary manslaughter, a lesser crime under Aruban law than murder, which requires proof of premeditation.