St. Lawrence County District Attorney Mary Rain said Sunday that computer hard drives and other evidence were still being collected from the home of Stephen Howells Jr. and Nicole Vaisey.
The pair was arrested Friday and charged with kidnapping with the intent to physically or sexually abuse the 7-year-old and 12-year-old sisters.
Rain says she "100 percent" expects more charges, which could come Monday or at a court hearing Thursday.
The sisters were abducted Wednesday from a farm stand in front of the family's home in Oswegatchie (ah-swee-GAH'-chee).
Rain said Saturday that the girls were sexually assaulted before being set free Thursday.
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