PORTLAND, Maine (AP) — Maine police investigating the disappearance of a 20-month-old girl from her father’s home two weeks ago say they now believe foul play was involved.

Waterville police Chief Joseph Massey announced Friday night the case “has evolved from the search for a missing child to a criminal investigation.” In a statement, he says the conclusion was based on evidence gathered over the past two weeks. He hasn’t elaborated.

Ayla Reynolds was last seen on Dec. 16. Her father told police he put her to bed that night in his Waterville home. He reported her missing the following morning.

Police previously said they believed someone had taken the girl from the home. Police have received hundreds of tips as they’ve searched for her.