Won't Know Till I Get There by Walter Dean Myers [1988 HARDCOVER]
VINTAGE HARDCOVER  PUFFIN BOOKS
Book is in excellent condition with just some subtle tanning to pages.
When Steve's parents decide to adopt a foster child, it seems like a good idea. And when Steve decides to show the new kid how tough he is by spray-painting the side of a subway car, that seems like a good idea too. But the foster child turns out to be a thirteen-year-old with a criminal record, and the guys in the designer jeans watching Steve spray-paint graffiti turn out to be transit police. Suddenly Steve and the whole gang are serving time, working in an old-age home with a bunch of feisty and independent senior citizens who refuse to sit still and be stereotyped - by anybody.