international manhunt under way at this hour for a suspected killer and kidnapper on the run. You see him here. A san diego man accused of abducting a teenage girl, killing her mother, possibly her... See More
international manhunt under way at this hour for a suspected killer and kidnapper on the run. You see him here. A san diego man accused of abducting a teenage girl, killing her mother, possibly her younger brother, as well. And then, setting their home on fire. Abc's brandi hitt joins us from los angeles, with the very latest. Good morning, brandi. Reporter: Overnight, the amber alert for the missing teen expanded after someone spotted a car thay be the suspect's. In an exclusive interview with abc news, his sister says police are searching for the wrong man. Here's a picture of our suspect. Reporter: This morning, a possible sighting in the international manhunt for 40-YEAR-OLD james DiMaggio. The man police believe kidnapped 16-year-old hannah anderson, after allegedly torching this house and killing her mother inside. Overnight, police said someone in oregon spotted a car matching the description of the one they believe DiMaggio is driving. Earlier wednesday, investigators had expanded their search to include mexico and canada. Overnight, issued new amber alerts in oregon, washington and nevada. She was the kindest, sweetest soul that you could ever imagine meeting. And completely incapable of hurting anyone. Reporter: In an exclusive interview with abc news, DiMAGGIO'S SISTER, LAURA, Described his close friendship with the andersons. And believe he, too, is the victim of foul play. AMID THE ASHES of DiMaggio's home, detectives found the unidentified remains of a child. Close friends believe it's hannah's 8-year-old brother, ethan. He tried to take care of those kids. And he took care of them as if they were his own. Reporter: In fact, friends SAY THE CHILDREN knew DiMaggio as uncle jim. But that recently, hannah voiced concerns. I know hannah did say she was a little creeped out when jim did tell her that he had a crush on her. Reporter: Authorities won't comment on possible motives in this case. But after speaking with detectives, hannah's father made THIS DESPERATE PLEA to DiMaggio. I'm begging you to let my daughter go. You've taken everything else. Hannah, if you have a chance, you take it. You run. Reporter: Laura dimaggio told me her heart goes out for the anderson family. And she's praying for them, as for the safe return of her brother.
This transcript has been automatically generated and may not be 100% accurate.