The adoptive parents said she was missing and went on air begging for help.
A 46-year-old man will appear in court on Tuesday, charged with arson and murder.
The gun-wielding intruder was eventually shot dead.
Members of the public broke down as details of her death were heard.
Her burnt body was found near the Rakaia River in May 2016.
"This is not goodbye; it's see you later... Love you, Amber."
Police are also interested in identifying two vehicles.
The 78-year-old man was treated for a gunshot wound but died at the scene.
"I promised you that you would never be alone, and you won't, not ever."
Police say the 30-year-old suspect knew the victim.
The 18-year-old was attacked when his vehicle stopped at the intersection of Wellesley St and Queen St.
The pair recovered from the wreckage of a house fire may have died before the blaze began.
The gunman who shot Ho Ledinh while he was drinking coffee is still at large.
A script has been written and the hunt is on for actors and locations.
The public is outraged - but her family doubts justice will be done.
The 26yo is charged with the murder of a man who was dropped off at Tauranga Hospital.
A 26-year-old man has been accused of murder after a man was dumped outside Tauranga Hospital.
A 17-year-old girl has been arrested and charged.