he got mixed up with a gang of skateboarding delinquent kids and got arrested by Officer Ponch and Officer John?

Maybe the Brady's threw him out for being a hoodlum.

It's sad, but I heard that he fell into a large container of acid while on a school field trip to a chemical factory.

He was adopted by Ted and Georgette Baxter.

A few years later in 1980 he helped Commander Adama lead the Galactica fleet to Earth.