( CNN ) -- A central Maine police chief said Friday that authorities now believe there was `` foul play '' in the disappearance two weeks ago of a 20-month-old girl . Ayla Reynolds was last seen December 16 when her father , Justin Dipietro , said he put her to bed . Dipietro -- who has insisted that he has `` no idea what happened to Ayla '' -- later reported the girl missing . Waterville Police Chief Joseph Massey previously has said authorities were confident that someone took Ayla from the house . But in his comments Friday , issued in a statement , Massey went a step further in saying the case `` has evolved from the search for a missing child to a criminal investigation . '' Given this shift , the Maine State Police will now take over as the lead in the investigation from Waterville police , according to Massey . `` We base our conclusions on evidence gathered by investigators during the past two weeks , '' the police chief said . Maine state police did not respond immediately to a call Friday from CNN seeking comment on their new role in the investigation . Jessica Reynolds , the missing girl 's aunt , told CNN on Friday that authorities said they `` ca n't tell us right now '' about what evidence spurred the change , claiming they were told `` it is n't done being processed . '' `` We believed from the beginning that Ayla did n't walk out ( of the house ) on her own , '' Reynolds said . `` Why it took 14 days for police to say this , I do n't understand . `` Time is ticking . The statistics may be that she 's not going to come home alive , but , there 's also a chance that whoever has her will bring her back safely ... Whoever has her will be found eventually . '' Police said Wednesday they had received 370 leads , and Massey said Friday that investigators and searchers had spent `` many thousands of hours looking for Ayla ( and ) evaluating evidence . '' A $ 30,000 reward -- coming from anonymous private citizens and business leaders -- was offered earlier this week for information that leads investigators to the girl . Ayla is described as having blond hair , being about 2 feet , 9 inches tall , and weighing 30 pounds . She was last seen wearing green pajamas with white polka dots and the words `` Daddy 's Princess '' across the front . When she disappeared , the girl had her arm in a soft cast . The toddler 's mother , Trista Reynolds , told HLN 's Nancy Grace that she 'd raised Ayla for 18 months and Dipietro became involved after `` I needed to go and get a little bit of help for myself . '' She told HLN she underwent rehab . The father had sole custody of the girl when she disappeared . On December 15 , the day before Ayla went missing , Reynolds filed a complaint seeking sole custody . The 23-year-old mother told HLN she did n't tell Dipietro she was going to court because he was `` vindictive '' and `` verbally abusive . '' For his part , Dipietro , 24 , has said he would never do anything to hurt Ayla . `` I have to believe that Ayla is with somebody , and I just want that person to find the courage to do the right thing and find a way to return her safely , '' the father said in his statement Wednesday . `` The truth is the truth and when the case is solved it will be out there . Until then , please try to remain positive and hopeful as I remain confident that Ayla will return safely . '' Jessica Reynolds said Friday that she and her sister , Trista , are frantic in their efforts to find Ayla . `` She 's extremely intelligent , '' she said of her niece . `` She makes everybody smile when they see a smile on her face . '' CNN 's Ross Levitt and Susan Candiotti contributed to this report .
The case has `` evolved '' from a missing child case to a criminal probe , police chief says . Ayla Reynolds ' father says he has n't seen the girl since putting her to bed December 16 . He says he has `` no idea what happened '' to the 20-month-old girl .