The man accused of taking illicit photographs of the bedridden wife of U.S. Sen. Thad Cochran has been indicted on burglary charges.

Clayton Kelly was served Wednesday with an indictment charging him with one count each of burglary, attempted burglary and conspiracy to commit burglary, said Madison County District Attorney Michael Guest.

Kelly's lawyer, Kevin Camp, told The Associated Press that his client picked up an indictment at the Madison County courthouse that grand jurors returned weeks ago. Camp said Kelly waived his arraignment and pleaded not guilty. A trial is set for March.

A Pearl resident, Kelly was released in May on $75,000 bond after his arrest on charges of exploitation of a vulnerable adult, filming without permission and conspiracy. Camp said his client wasn't re-arrested Wednesday and remains free on that bond.

Police say Kelly photographed Rose Cochran, without permission, in a Madison nursing home and posted her image online. Investigators have said conspirators intended to use images of the woman to advance allegations that her husband, the senator, was having an inappropriate relationship. Thad Cochran has denied any inappropriate acts.

Rose Cochran has been institutionalized with dementia since 2001, has lost the ability to speak and is receiving hospice care, according to her family. Cochran's challenger in the Republican primary, state Sen. Chris McDaniel of Ellisville, has denied having anything to do with photographing the senator's wife.

Guest said in a telephone interview that the attempted burglary charge related to a previous occasion when Kelly tried to enter the nursing home and failed. He said the burglary charge related to Kelly's taking the picture on April 20. He said that all charges allege that  Kelly broke in to exploit a vulnerable adult, not to steal property, the allegation associated with most burglary charges.

Camp said that the changing nature of the charges show that prosecutors are having a hard time finding a statute that clearly defines what Kelly did as a crime.

"The charges have changed at every step, from where they were at the first day of court, to where they were at the second day of court to now that he's been indicted," Camp said.

Guest said prosecutors remained in plea negotiations with another man arrested in the case, Richard Sager, of Laurel. A third man, John Mary, of Hattiesburg, pleaded guilty in August to one felony count of conspiracy to commit a computer crime and was sentenced Mary to five years' probation and no fine.

A fourth man, attorney Mark Mayfield, of Ridgeland, committed suicide at his home on June 27, authorities said. All four men were McDaniel supporters.

Guest had made earlier statements raising the possibility that others besides those four might be charged. Wednesday, though, he said that was unlikely.

"At this point, based on the information we have, I do not expect there to be any other arrests or any other indictments," Guest said.