Now to the search for a missing newborn if Wisconsin. Kayden Powell disappeared from his home at just 5 days ole. Police say a person of interest is in custody but still no trace of the baby. ABC's... See More
Now to the search for a missing newborn if Wisconsin. Kayden Powell disappeared from his home at just 5 days ole. Police say a person of interest is in custody but still no trace of the baby. ABC's Mara schiavocampo is here with this story. This is just heartbreaking. Really heartbreaking story and just seems like the unthinkable. A baby simply vanishing in the middle of 9 night. Now federal officials are among the 40 law enforcement officials assisting in the search but so far there seem to be more questions than answers. Looking through dumpsters, canvassing streets, interviewing neighbors, all part of the massive search for a newborn who simply disappeared in the middle of the night. Kayden Powell is just 6 days old. Early Thursday morning police responded to a 911 call from the infant's mother that he was gone. Investigators continue to evaluate the information being comp compiled. At this time no suspects have been identified and no arrests have been made. Reporter: Officials say the baby's mother, 18-year-old Brianna Marshall says she woke up to find her son gone, missing from his bassinet. The baby's father, 23-year-old Bruce Powell and two other family members were also staying in the house including Kristin smith who left for her own home in Colorado around 1:30 A.M. The last those in the house remembering seeing the baby. Hours later, law enforcement officials arrested smith on an outstanding warrant 170 miles away but say she is not a person of interest in this case. I'm already devastated because he's gone. I've had my great nephew one time and that was yesterday. Reporter: Now the FBI has joined local and state police in the investigation. They say there were no signs of a break-in at the home and the parents are cooperating. Meanwhile, police say they're following up on other leads and desperately hope one of them will lead to little Kayden. This is a difficult time for the family. We are trying with every resource we have to try and reunite this family. Reporter: Police say no amber alert was issued for Kayden because there was no description of a suspect or a vehicle. Kayden is just 6 pounds and 20 inches long and, of course, if anyone has any information, they are encouraged to contact the FBI.
This transcript has been automatically generated and may not be 100% accurate.