DETROIT -

The case of a 12-year-old Detroit boy found alive in his father’s basement after being reported as missing for 11 days took a strange turn Thursday evening.

Detroit police and Child Protective Services descended on the Lafayette Park condo and arrested Charlie Bothuell's stepmother on a probation violation and removed two other children -- a 4-year-old boy and a 10-month-old girl -- from the home.

While police continue to delve into exactly what was going on in the Bothuell home, sources have given Local 4 new details on the investigation.

Police said they believe the 12-year-old boy was in the basement the entire time he was missing and that he would come upstairs when he thought the coast was clear in order to eat.

What precipitated the boy to hide? Sources said home-schooled Charlie was on a strict regimen and his father had been on him about his weight. He was required to do 4,000 strides on an elliptical trainer without a break.

Police said the 12-year-old was in the middle of his exercise routine when he desperately had to go to the bathroom and got off the machine. His stepmother reported that transgression to his father, and allegedly the boy was afraid of what was going to happen to him.

Police are now trying to determine whether either the boy’s stepmother or father knew he was barricaded in the basement and whether the behavior in that home was over the line.

Police found blood on a PVC pipe and on some clothes in the father's room that's being tested. Whether it has any significance is not yet clear.

After police arrested his wife and removed two other children from the home, Charles Bothuell IV told Local 4 he couldn’t comment on the case but said, "I appreciate everybody getting the word out. I appreciate the work that everybody did -- the Detroit police, the FBI, the media -- everything to find my son and I'm glad he's safe. I'm thankful and I just have no further comment at this time."