AUGUSTA — A Waterville man who formerly worked with the Boy Scouts of America as a volunteer pleaded guilty Tuesday to a charge of possessing child pornography.

Charles H. Tisdale Jr., 28, originally was charged with two counts of possession of sexually explicit materials of minors under 12. However, one charge was dismissed by the prosecutor in exchange for the plea.

Tisdale was sentenced to two years in jail, with all but six months suspended, and two years’ probation. Conditions of probation prohibit him from unsupervised contact with children under 16, except for his own, and from possessing devices that can connect to the Internet. The conviction means he will be a 10-year registrant under the state’s Sex Offender Registration and Notification Act.

The guilty plea and sentencing took place in a Kennebec County Superior Court case heard in the Capital Judicial Center.

Assistant District Attorney Frayla Schoenfeld said dismissal of the second charge means Tisdale will not be a lifetime registrant.

The charges stemmed from a 2011 investigation by computer crimes officers, Schoenfeld said, and resulted in them finding 23 images of children under 12 engaged in sexually explicit conduct. She said the images were on Tisdale’s work laptop computer, which was in the trunk of his vehicle.

At the time of Tisdale’s arrest in June 2011, Waterville police said Tisdale had been affiliated with the Boy Scouts for the last six years and that he had regular contact with children through his employment with Sequel Care of Maine and Employment Specialists of Maine. They also said there was no evidence that Tisdale has had any criminal contact with children.

“Police believe that the images recovered on Tisdale’s computer were downloaded from the Internet, and they have no evidence to indicate that the images were shot locally,” a statement from Waterville police said. “No evidence has been gathered to suggest that Tisdale has had inappropriate contact with any area youth.”

Tisdale’s registration with the Scouts was revoked in 2011 as a result of the charges, according to a district executive at the time. Tisdale’s work had been largely with adult volunteers.