WICHITA, Kan. (AP) — Authorities say the search for a 5-year-old boy who’s been missing for three months is “very challenging” and are encouraging the public to keep looking and providing tips.

Organizers planned to gather and search again on Sunday, according to the Find Lucas Hernandez Facebook page.

Police discussed the search Thursday, one day after Lucas Hernandez’ stepmother, Emily Glass, was acquitted of child endangerment. Prosecutors alleged she drove her 1-year-old daughter to a restaurant while high on marijuana on Feb. 16. Lucas was reported missing the next day.

Sedgwick County District Attorney Marc Bennett says Glass is a “person of interest” and a witness in Lucas’ disappearance.

Capt. Brent Allred says police are “disappointed” that Lucas hasn’t been found and will follow up on any leads that the public provides. He says police “don’t have any information to follow up on right now.”