The Cape and Islands district attorney has dropped charges against a Tisbury man accused of child rape, citing the age of the victim.

Richard McElhinney, 48, of Tisbury, was arraigned in Edgartown District Court May 20, on a charge of child rape, indecent assault, and enticement of a child. The court entered not guilty pleas on his behalf.

Mr. McElhinney is a Tisbury School custodian. After his arrest, the school placed Mr. McElhinney on administrative leave with pay.

According to police reports, the alleged assault took place in a school bathroom, after school hours. The child, who is not related to Mr. McElhinney, was under his supervision.

Assistant district attorney Genevieve Henrique notified Edgartown District Court on August 12 the office no longer intended to prosecute Mr. McElhinney. In a court filing termed a “nolle prosequi” she said the Commonwealth was “unable to proceed at this time due to the victim’s age.”

“‘Nolle prosequi’ is a mechanism the prosecutor has to postpone the prosecution of a case for a reason that has to be outlined in the nolle prosequi document itself,” first assistant district attorney Brian Glenny told The Times in a telephone conversation Monday. “I’m not going to comment specifically about this case. I will tell you in a lot of prosecutions that involve these types of allegations, you’ll have a child that is of such tender years that it would not be a great benefit to a child to have to put them through the process that it would require to achieve a conviction.”

The state’s decision to file a nolle prosequi leaves open the possibility that Mr. McElhinney could face charges in the future.

“It could be brought back if the reasons that were outlined in the nolle prosequi change,” Mr. Glenny said. “Obviously as the child gets older, the situation could certainly change.”

In a telephone message left with The Times Thursday, Mr. McElhinney asked that news of the state’s decision be reported. Contacted by phone Tuesday, Mr. McElhinney declined to comment. “I’ve been told by my lawyer not to speak about it,” Mr. McElhinney said. “I really don’t have much to say.”

Asked if he planned to seek his custodian’s job back, he declined to comment.