An indictment made public on Friday kept the kidnapping charge and added four of predatory sexual assault against a child, along with charges of sexual abuse, assault and endangering the welfare of a child.
Ross pleaded not guilty in the Saratoga County Court.
A phone message seeking comment was made to his lawyer.
District Attorney Karen Heggen said afterwards that the defendant had committed a heinous offence against a young victim.
“We will hold him accountable and responsible,” she told WNYT-TV.
The 9-year-old girl had been riding her bike around a campsite loop in the park with other children on a Saturday evening when she decided to ride around one more time by herself. Her parents became alarmed when she failed to return after about 15 minutes.
An amber alert was issued the next morning and more than 100 police, forest rangers and civilians took part in a search that employed drones, bloodhounds and an airboat. Troopers set up checkpoints on the winding rural roads around the park.
Ross has been in jail without bail since his arrest.
