AUBURN – The prosecutor who successfully argued his murder case last month against Daniel Roberts has said the conviction should stand.

Deputy Attorney General William Stokes wrote in Androscoggin County Superior Court papers that the reasoning behind Roberts’ claim of alleged impropriety on the part of one or more grand jury members who indicted him is flawed.

Stokes said Roberts’ motion was untimely, didn’t merit any further court action and doesn’t apply to the jury trial and subsequent conviction of the defendant.

Roberts’ attorney, Leonard Sharon, had filed a motion seeking to dismiss the indictment that led to the defendant’s guilty verdict and vacate the conviction.

Sharon said a female jury member and her boyfriend conducted their own investigation during the life of the grand jury. They even visited the murder scene at 81 Roberts Road in Sabattus, Sharon said.

The boyfriend later posted on the Sun Journal’s Web site about the visit, but said during an interview with a reporter that their visit took place long before her grand jury selection.

Sharon also claimed grand jury members communicated with each other and a third party. Those discussions tainted their deliberations and the murder indictment against Roberts handed up on Dec. 6, 2005, Sharon said.

Stokes addressed Sharon’s motion in his answer filed Monday.

First, Stokes said he couldn’t find a single case in Maine where a court considered dismissing an indictment after a jury had convicted a defendant on a charge stemming from that indictment.

Motions objecting to the merits of the indictment must be brought to the court before trial, according to Maine Rules of Criminal Procedure. For that reason, Sharon’s motion is untimely, Stokes wrote in his response.

“Entertaining such a motion at this post-verdict stage would be highly unusual and improper and would serve no purpose given the fact that a traverse jury has unanimously found the defendant guilty,” Stokes wrote.

Stokes also made the point that the standard of impartiality for a trial juror is not the same as that for a member of a grand jury. Grand jurors are “free to communicate with each other,” Stokes wrote. “There is nothing in the law that prevents that or that renders it improper.”

Even if a member of the grand jury visited the site of the killing, there is “nothing in law that renders this conduct improper or unauthorized,” Stokes said.

Finally, Stokes said, it wouldn’t matter even if members of the grand jury had acted improperly.

He cited cases in which alleged grand jury irregularities were rendered irrelevant by a trial jury’s guilty verdict.

Justice Joyce Wheeler, who presided over Roberts’ murder trial, will review Sharon’s motion and Stokes’ response to it to determine if there’s enough merit to the motion to warrant a hearing.

Meanwhile, no date has been set yet for sentencing Roberts.