A detective fielded questions from a defense lawyer for most of Friday's session in the trial of a former Rutgers student accused of using a webcam to spy on his roommate's intimate encounter with another man.

Defense lawyers for Dharun Ravi called investigator Frank DiNinno to testify.

Defense lawyer Steven Altman spent about four hours grilling him about details of the investigation. He zeroed in particularly on interviews with one Rutgers student who changed his story.

Ravi faces 15 criminal charges, including invasion of privacy and bias intimidation. His roommate, Tyler Clementi, committed suicide in September 2010, days after the alleged spying.

DiNinno is expected to be back on the stand Monday morning.

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