Werking said there were over 1,600 DVDs and tapes.
In one email, Werking's father told him he did him a "big favour by getting rid of all this stuff".
"There is no question that the destroyed property was David's property," Maloney said Monday.
"Defendants repeatedly admitted that they destroyed the property."
Werking's parents said they had a right to act as his landlords.
"Defendants do not cite to any statute or caselaw to support their assertion that landlords can destroy property that they dislike," the judge said.
Maloney told both sides to file briefs on the financial value of the collection.
"The court does not intend to hold an evidentiary hearing," he said.