Trainman

Answer: The parents do not notice when the little girl leaves the bathroom and are never seen or heard from again. Presumably they believed their daughter to be missing and an investigation would be launched, but the girl would not be found until after Riot had switched bodies and she was killed.

BaconIsMyBFF

Answer: He wanted to eventually use it as a biological weapon.

raywest ★

Answer: Is it because if anyone knew about it will spread information across the globe and will likely lead to his enemies and will no longer be a secret and his plans will be ruined?

Trainman

Answer: Maybe she was afraid at the time.

Answer: He's simply enjoying doing it himself. Especially since he likely believes he can do it better than she can.

Answer: Because he's a rich, spoiled, self-centered bully who sees the Goonies as low class weirdos who are getting in the way of his father's development plans (and he sees Brand as as rival for Andy's affections).

Brian Katcher

Answer: If it was ever found out that she was at Terry's house before he was killed, there's a possibility that a lot of people would have begun to suspect her of murdering Terry. By claiming that she wasn't, she was hoping that people wouldn't accuse her of the murder.

Answer: I believe his dog was found in a different county (Brookville) and held in a kennel or shelter with the assumption that Joe (or his father) needed to pick her (Lucy?) up.

KeyZOid