The Attorney General’s office said today that it will not pursue criminal charges in the case of a 17-month-old toddler who was severely injured while under the care of his babysitter in 2015.

The office said it took the unusual step earlier this year of convening an investigative grand jury, which heard testimony from multiple members of the sitter’s household, but a suspect in Peyton Valiente’s assault could not be identified.

The Honolulu Police Department previously had investigated the case but acknowledged that it fell short in that investigation, and prosecutors determined there was insufficient evidence to pursue a case. After that, the case was referred to Attorney General Doug Chin’s office.

“It was difficult to have to break the news to the parents, Chelsea and Rey Valiente, that our findings did not result in charges against a perpetrator,” Chin said in a news release. “Despite the outcome, we hope they receive some comfort by the renewed efforts to identify Peyton’s assailant and bring that person to justice.”