An autopsy was scheduled Tuesday on the body of the 3-year-old girl that was discovered Monday in a trash bag dumped in a ravine at Lakewood Gulch Park.Police officers found the body of Niveah Gallegos in a wooded area at 11th Avenue and Perry Street at about 4:45 p.m.The grim discovery ended a four-day search centered in Denver's Capitol Hill neighborhood, where police made a plea to the public to look through their Dumpsters and outdoor trash bins for the girl's body."The body was found in much like we were expecting to look for," said Lt. Ron Saunier, with the Denver Police Department. "This is an emotional deal," he said. "Anytime you have a kid involved, it is a tragic situation."Police believe they believe Niveah was dumped by her mother's boyfriend Friday afternoon.Niveah's mother had initially claimed her daughter had been kidnapped. But when questioned about it on Friday, she broke down and admitted to police that her 3-year-old was dead and stuffed in two plastic bags, according to arrest affidavits released Monday.Miriam Gallegos, 20, told officers that while she was at work Friday afternoon, her boyfriend called her and told her to come home right away, but wouldn't say why.Gallegos, who works at the Sports Authority on 10th and Broadway, said she walked home and found that her daughter was not breathing. She said she tried to resuscitate Niveah but failed.Gallegos said she and her boyfriend, Angel Ray Montoya, were scared. So instead of calling an ambulance or police, they both decided to place the girl in a white plastic trash bag, cover that with another black plastic bag and place that bag in a royal blue duffel bag with yellow handles, according to the arrest affidavits.Then she said they both went to an alley behind their apartment and she and Montoya went in separate directions, according to the affidavit. She told officers that the last she saw of Montoya, he was carrying the duffel bag with Niveah inside, and walking northbound.Hours later, when police arrested Montoya, he was carrying a duffel bag, but it was empty. Police initially thought he disposed of the girl somewhere in the Capitol Hill neighborhood. Investigators also said Montoya had a bus pass, so it was possible he took a bus or light rail somewhere to get rid of the body.The area where the girl was found is four miles west of the couple's apartment on 13th Avenue and Logan Street.Police began investigating the case on Friday at 3 p.m. when Gallegos called 911 saying that her daughter was snatched from her arms in the alley near their home.When detectives went to her apartment to get a photograph of Niveah, they noticed "a paper towel on the floor of the living room that had blood or some other type of body fluid on it," the affidavit said.Officers questioned her further about the alleged kidnapping and that's when Gallegos "spontaneously" told detectives that "she and her boyfriend ... were scared and put the baby into a bag," the affidavits said."It is a shame that this happened and the truth is, the man who we all think around here is the father, should have never been allowed to see her," said Elizabeth Murray, the grandmother's next door neighbor. "Because something like this was bound to happen, he was crazy."Montoya's arrest affidavit also stated that in July 2006, Montoya was investigated in connection with an alleged sexual assault on "a victim." The case was dropped because Gallegos would not cooperate with police.Meanwhile, neighbors living near Niveah's grandmother's house said they often saw Gallegos and Montoya yelling at each other in the street. They said Niveah and Gallegos lived at the grandmother's home for a while, and that the grandmother basically raised the child."(The grandmother) is a mess. She's walking around all the alleys and checking all the trash cans trying to look for her granddaughter," said Murray. "It's just a shame that that man got ahold of that little baby because that never should have happened."Gallegos is now being held on suspicion of being an accessory to the slaying and on suspicion of filing a false report.Montoya is being held on charges of first-degree murder.Montoya is a registered sex offender and has been convicted of child abuse and indecent exposure to minors and adults. He has also been arrested on charges of kidnapping, according to police records.Gallegos also has a criminal history. In 2006, she was accused of possession of marijuana and found guilty of possessing drug paraphernalia.