UPDATE: Shaylyn Ammerman's body was found on the evening of March 24. Details here: http://bit.ly/1XSu5O7
"No one has been ruled out until she's been brought home," Sgt. Curt Durnil said at a press conference Thursday.
Police launched a search Wednesday after she was reported missing from her father's home in Spencer, Indiana.
PREVIOUS | 1-year-old missing from father's home in Spencer
Polygraphs have been administered to two to three people, including the girl's father.
"She's been missing for over 24 hours. We're worried. We're worried. It's not something we think is good right now, okay. There's hope, we're obviously, our folks are out in the rain searching, been slowed down by the weather, but not going home," Durnil said.
Durnil expects more polygraphs will be given in the future. He added that everyone that has been questioned has cooperated.
"Not necessarily that would be named suspects, or guilty of anything but just people that we think have information that will be helpful to us," he said.
A number of police agencies are involved in the search, including the FBI. Indiana conservation officers are using sonar equipment. The National Center for Missing and Exploited Children is also on scene.
Evidence such as computers and cell phones have been collected and examined.
PHOTOS: The search for Shaylyn Ammerman
"We're not leaving any stone unturned in this case. We're asking folks to continue to call us with any tips, with any information that they think might be significant or insignificant. We're opening manhole covers, we're searching dumpsters, we're searching everywhere that we think Shaylyn might be or might be placed," Durnil said.
Search and rescue crews have been using K9s, boats and ATVs to search an area that includes Owen County along the White River, Freedom to Gosport and into Morgan County.
"We're gathering information as to where persons of interests were at the time that the child was missing, where they went, where they're telling us they went. The facts that we know, where their car was parked, that type of thing, what route they must have taken. A child is missing and the house that the child is missing from is right over the hill from the White River," he said.
Shaylyn was at her grandmother Tamera Morgan's house, where her father, Justin Ammerman, lives, at the time of her disappearance. Morgan said at the time of Shaylyn's disappearance, the front door was unlocked.
"When you talk about unlocked doors or unlocked windows, there's not a lot of evidence that's left there. If you leave a door unlocked or a window unlocked or something that someone can just come right in and leave, perhaps not a lot of evidence was left to substantiate that claim. So we're looking at all those angles," Durnil said.
However, police say they are confident that Shaylyn's mom does not know where she is.
An Amber Alert has not been issued because the case does not meet the criteria.
"It's unfortunate because in an Amber Alert, we either have to have a vehicle, suspect vehicle, or a person, a suspect person, right now we have neither. We don't know who actually took the baby, how the baby got out of the house. So without those two criteria, Amber Alert, that's not going to be met," he said.
MORE | Why no Amber Alert for Shaylyn Ammerman?
State police say they have been contacted by several people who want to coordinate a reward for the safe return of Shaylyn are looking into setting one up.
Police also say that some of the search and rescue teams have been slowed down due to onlookers and cars following too closely to their vehicles.
Anyone with information about Shaylyn's whereabouts is asked to call the Indiana State Police at the Bloomington Post at 812-332-4411.
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