Isabel Celis disappeared from her family’s Tuscon, Arizona, home sometime in the early morning hours of April 20, 2012. Despite a massive search and intense police investigation, the child is still missing nearly five years later.

An open screen suggests the six-year-old was snatched from her bedroom through the window, but there were no obvious signs of a struggle. Security camera video recorded by a business down the block does not show Isabel being taken away in the front of the home. A high wall encloses the residence’s backyard.

The father’s remarkably calm call to a 911 dispatcher initially drew attention to him. Investigators have also looked at a man who lived with the family for a while.

Nancy Grace has closely followed Isabel’s case since the beginning. She discusses the latest in the investigation with Alan Duke for this episode of “Crime Stories with Nancy Grace.”

[Feature Photo: Family Handout]