BANGOR, Maine — An Illinois man was acquitted of possessing child pornography by a jury Thursday, according to the Penobscot County district atorney’s office.

Scott A. Nadolski, 23, Carbondale, Ill., was indicted in February by the Penobscot County grand jury on two counts of sexually explicit material.

The trial began on Tuesday, Tracy Lacher, assistant district attorney for Penobscot County, said Friday. The jury deliberated for more than an hour on Wednesday before going home for the night. They returned and deliberated another four hours Thursday before announcing the verdict.

Two depictions of child pornography were found last year on a laptop computer Nadolski gave a former girlfriend he lived with in Orono in the summer of 2011, defense attorney Steven Juskewitch of Ellsworth said Friday. She went to Orono police in March 2012 and reported finding child pornography on the computer.

Juskewitch said that his client, who graduated from Maine Maritime Academy earlier this year, admitted downloading adult pornography but denied downloading child pornography. The images were stored in a zip file.

“Our computer expert testified that those two images were unviewable until the file was unzipped by his former girlfriend,” Juskewitch said.

Lacher said that the images of child pornography were found in a collection of adult pornography. She also said that from statements Nadolski made to police and in text messages to his former girlfriend, a jury could have concluded that he had admitted to viewing similar photos in the past.

Scott Lavoie, owner of Saturn consulting and Digital Forensics Co. in Bangor, testified as an expert for the defense. He said the circumstances that led to the prosecution of Nadolski should serve as a warning to others about downloading free adult pornography.

Lavoie said that purchasing adult pornography from “a firm with a reputation and reliability behind it” is the best way for people to avoid inadvertently downloading child pornography.

“I don’t want people who download child pornography to be free,” he said. “But in [Nadolski’s] case, from an evidence standpoint, the prosecution couldn’t prove beyond a reasonable doubt that he knowingly possessed child pornography.”