An attorney for a photographer accused of threatening to sell topless photos of actress Cameron Diaz (search) opened his case Tuesday with testimony that his client was conscientious about getting models to sign releases.

John Rutter (search), 42, is charged with attempted grand theft, forgery and perjury. An extortion charge was dropped.

Prosecutors allege Rutter forged Diaz's signature on a photo release form and attempted to sell pictures he took a decade ago back to her for $3.5 million.

His former agent Frank Moore testified that Rutter was vigilant about getting models to sign releases that were standard for his photo shoots.

On cross-examination, however, Moore said he did not know if Diaz actually signed a release.

After the prosecution rested earlier in the day, Los Angeles Superior Court Judge Michael Pastor denied a request by Rutter's attorney Mark Werksman to dismiss the case.

Diaz testified last week that she never signed a release for the 1992 shoot. Two forensic experts called by the prosecution testified signatures on the release appeared to be forged.

Rutter is accused of offering the pictures to Diaz before her film "Charlie's Angels: Full Throttle" was released in 2003 and threatening to sell the images to the highest bidder if she declined to buy them.

If convicted, Rutter could face up to six years in prison.

A judge has issued a permanent injunction prohibiting him from distributing the photos.