ALBANY, May 8 (Reuters) - Viewing child pornography on the Internet without taking further action such as printing or saving files does not necessarily constitute possession, NewYork's top court ruled on Tuesday.

The ruling by the Court of Appeals dismissed two of the 143 counts of possession of child pornography for which James Kent, a former professor at Marist College, was convicted in 2009.

When a Web page is viewed, a copy of the page is stored in a computer's "cache," which allows that page to load more quickly on future visits. The court found that while Kent had saved some of the files in question, he had only viewed others and was not aware of his computer's cache function.

To "possess" cached images, "the defendant's conduct must exceed mere viewing to encompass more affirmative acts of control such as printing, downloading or saving," Judge Carmen Ciparick wrote for the court.

Prosecutors must show, "at a minimum, that the defendant was aware of the presence of those items in the cache," Ciparick continued.

In 2007, Kent asked information technology staff at Marist to look at his computer because it was not working properly. A college employee discovered numerous photos and videos of young children, some of whom were nude. The school turned the computer over to police.

A forensic investigator found more than 30,000 additional files in Kent's computer's cache.

In his defense, Kent said he had used the images as part of his research into child pornography. He further argued that he had never been in possession of many of the files because they were not saved to his computer.

Kent was convicted after a non-jury trial of 143 counts of possession and sentenced to one-to-three years in prison. In 2010, the Appellate Division, Second Department, affirmed the conviction, holding that a "cached web page ... is evidence that the web page was accessed and displayed on the defendant's computer screen."

The Court of Appeals on Tuesday modified, tossing out two of the counts because they involved files that Kent never purposely saved to his computer.

"A defendant cannot knowingly acquire or possess that which he or she does not know exists," Ciparick wrote, joined by Chief Judge Jonathan Lippman and Judges Susan Read and Theodore Jones.

Judge Robert Smith concurred in a separate opinion.

Judge Victoria Graffeo concurred in result, but wrote that the majority opinion was too broad and essentially legalized the viewing of child pornography in New York. That, she said, goes against the state legislature's intent to punish consumers in order to eradicate the market for child pornography.

"The majority's decision ... will, unfortunately, lead to increased consumption of child pornography by luring new viewers who were previously dissuaded by the potential for criminal prosecution," Graffeo, joined by Judge Eugene Pigott, wrote.

The majority noted that, under federal law, it is a crime to "knowingly access (child pornography) with intent to view," while state law includes no comparable language.

Nathan Dershowitz, who represented Kent on appeal, said Tuesday that the issue is a prime example of the inapplicability of laws that predate the digital age to cases involving the use of computers.

The decision "indicates not that viewing child pornography is legal, but that the legislature has not dealt with this outdated language," Dershowitz said.

Kent's case was sent back to Dutchess County Court for resentencing.

Dutchess County Assistant District Attorney Bridget Steller did not return a call seeking comment.

The case is the People v. James Kent, New York State Court of Appeals No. 70.

For the prosecution: Dutchess County Assistant District Attorney Bridget Steller

For Kent: Nathan Dershowitz

(Reporting by Dan Wiessner)

Follow us on Twitter: @ReutersLegal | Like us on Facebook