The child pornography trial of Maine’s former top drug prosecutor opened this morning at federal court in Portland.

James M. Cameron, 47, of Hallowell, is charged with 15 counts of transporting, receiving and possessing child pornography. Cameron waived his right to a jury. The bench trial is being presided over by U.S. District Judge John Woodcock Jr.

Police began investigating Cameron, a former assistant attorney general, after Yahoo! reported finding images of child pornography in the photos section of an account holder later identified as Cameron’s wife. He was indicted by a federal grand jury in February 2009, and has been free on bail with some restrictions.

Each count of transportation and receipt of child pornography is punishable by a minimum of five years and a maximum of 20 years in prison. The possession counts are punishable by up to 10 years in prison.

The lead government prosecutor, Assistant U.S. Attorney Donald Clark, passed on his opportunity to make an opening statement to Judge Woocock this morning.

Michael Cunniff, Cameron’s lawyer, said the government cannot prove beyond a reasonable doubt that it was Cameron who possessed, received or transmitted any of the images retrieved from Yahoo’s servers in connection with this case. Cameron had no access to the materials in question and he had no intent to access them, Cunniff said.

The trial is expected to last at least a week.