Now Playing: Teacher searches for a new kidney by asking drivers on the street

Now Playing: Accused Mollie Tibbetts killer makes first court appearance

Now Playing: Suspect led police to the body of Mollie Tibbetts

Now Playing: Judge denies bond for man accused of killing pregnant wife, daughters

Now Playing: Suspect arrested in case of missing Iowa student Mollie Tibbetts

Now Playing: Father in custody after 2 sons drown in river

Now Playing: Florida police searching for man seen on camera setting car on fire

Now Playing: Father dances with 2-year-old daughter after she undergoes chemotherapy

Now Playing: Surveillance video shows woman dragged, run over during robbery

Now Playing: Police helicopter crashes at training facility

Now Playing: News headlines today: Aug. 22, 2018

Now Playing: Houston bank employee charged with robbery for role in violent attack

Now Playing: Colorado man faces 9 felonies for alleged murders of pregnant wife, daughters

Now Playing: Undocumented immigrant charged with murder of missing Iowa woman

Now Playing: Video shows crash of police helicopter in Arkansas

Now Playing: Hurricane Lane strengthens to Category 5 storm as it nears Hawaii

Now Playing: St. Jude staff provides ‘no more chemo’ party for Memphis girl

Now Playing: Train derailment prompts evacuations in California

Now Playing: NYC police search for a mystery gunman who opened fire in high rise luxury apartment

Now Playing: Asia Argento responds to sexual assault allegation