WATERVILLE, Maine — Investigators put up crime-scene tape around the home of a 20-month-old girl who's been missing since last weekend and two of the state's top homicide prosecutors were called to the house Thursday as the search for her entered its sixth day.

Police are stilling treating Ayla Reynolds' disappearance as a missing child case, Waterville Police Chief Joseph Massey said.

Massey told reporters that the investigation is focused closely on the house and that the crime-scene tape surrounding it and the presence of the homicide prosecutors were merely investigative tools. He said police are also using cadaver dogs in an area near the city's airport in the search.

Ayla was living with her father, Justin DiPietro, who reported her missing Saturday. DiPietro told police he last saw her when he put her to bed the previous night. He said she was wearing green pajamas with polka dots and the words "Daddy's Princess" on them. She also had a cast on her broken left arm.

Her disappearance unleashed a flood of leads from a sympathetic public and a search by state and local police and game wardens in the central Maine city. The FBI also got involved.

More than 60 people, many of them mothers with young children, prayed, sang hymns and offered one another support and hope during a candlelight vigil Wednesday night for Ayla.

While residents volunteered to help canvass neighborhoods, police checked out trash bins across the city and FBI agents knocked on doors. Officials even went so far as to drain a stream a few blocks from DiPietro's home so wardens could get a better look, both from the ground and from an airplane.

Ayla ended up with her father after child welfare workers intervened while her mother, Trista Reynolds, checked herself into a 10-day rehabilitation program.

Reynolds, who completed the rehab, had filed court papers that she hoped would lead to the return of her daughter. The filing came the day before Ayla was last seen.

DiPietro addressed the public Tuesday night for the first time, saying in a statement he had "no idea what happened to Ayla, or who is responsible."

He said his family and friends would do "everything we can to assist in this investigation and get Ayla back home."

Reynolds said she began to question Ayla's care after the girl suffered a broken arm, which officials said happened in an accidental fall. She said that she and her family encouraged child welfare agents to check on Ayla, but that they didn't follow through.

The Maine Department of Health and Human Services has had no comment on the request. Confidentiality laws bar the child welfare agency from even confirming whether it's working with an individual or family.