BOSTON (CBS) – There is now an uphill battle for the prosecution in the groping case against actor Kevin Spacey on Nantucket.

“At this point, this case is done. It’s over with. It’s going to be dismissed,” said WBZ legal expert Jennifer Roman.

Spacey’s accuser pleaded the Fifth Monday, a move that Roman says speaks volumes.

“He did some things that were clearly, potentially would have exposed him to criminal sanctions, and he chose not to testify as a result there of,” Roman said.

But his mother, former Boston TV anchor Heather Unruh did take the stand, admitting under oath to tampering with evidence by deleting text messages from her son’s cellphone.

“She tampered with evidence. That’s hugely problematic and that alone could get the case thrown out,” Roman said. “She could face charges. There’s a potential of an obstruction of justice charge.”

Even her husband’s outburst in court could help Kevin Spacey’s defense team.

“It certainly suggests there was something to hide,” Roman said.

And without key evidence, the accuser and his cellphone, Roman says the case will likely get tossed out.

“The prosecution really has nothing,” Roman said. “They’re going to dismiss this case if the judge doesn’t do it for them.”

The judge is giving the prosecution one week decide whether to move forward with this criminal case or dismiss it altogether.