When does the madness end?  Another little kid missing.  Are there monsters out there or sick friends or family?  Isabel Mercedes Celis is a 6-year-old girl who is missing in Arizona. She was reported missing from her parents' Tucson home on Saturday, April 21. Police say that her mom and dad are not suspects.  Yet little is publicly known as to who is a person of interest.  A potential key witness has come forward; however, nothing has been released as to the witnesses account of the evening in question.

According to ABC, Tucson police describe the witness as one of five individuals seen on surveillance footage near the home of Isabel Celis on the night she disappeared. The video recorded outside a nightclub show three women and two men walking toward the Celis family home at approximately 1:30 a.m. on April 21. Isabel was last seen around 11 p.m. Isabel's father reported her missing the next morning at 8:00 a.m. According to ABC, a screen from Isabel's room had been removed. 

Is a monster on the loose?  Last month, a man allegedly entered a house and molested a girl half an hour north of the Tucson home where Isabel Celis disappeared.  Police say a white man in his 20s entered a house in Arizona's Pima County around 2 a.m. Monday and went into a bedroom where three sisters, aged 6, 8 and 10, were sleeping. The intruder reportedly molested one of the girls. While Pima County investigators say they that the two incidents are likely unrelated, who knows. Richard Kastigar of the Pima Co. Sheriff's Department may know more than what he is sharing with the public. In the meantime, U.S. marshals asked Mexican authorities to expand the search for Isabel to include hotels, bus stations and businesses in the town of Sonora.

Local bodies of water near the Tucson area have also been searched with no clue of the child. Sergio and Rebecca Celis, Isabel's parents, say they will "never give up" on finding their daughter. Isabel is just under 4 feet tall, weighs approximately 44 pounds. She has brown hair and hazel eyes. Anyone with any information about Isabel should call 520-88-CRIME.