Blood Money by Anne Cassidy
Jaz and Jack have a secret they're hiding from Bobby - they have fallen in love - or so Jaz likes to believe. But this secret fades into insignificance when Jack finds a bag full of money abandoned in a house near to his. The house had been raided by the local mafia, and someone had stupidly left behind the loot. It's a massive amount of money and Jack takes it without thinking about the consequences. All he knows is that this money means freedom, it means a life beyond the estate. He is sure Jaz and Bobby will feel that, too.
But someone else is after the money and Jack is in big trouble. Frightened, he convinces Jaz to hide it in her grandma's attic - they can take it bit by bit ... But Jaz is uneasy, not only with hoarding the illegal booty, but also with Jack's new attitude to her - all of a sudden he is blowing hot and cold ... has Jack got a secret of his own?
Jaz doesn't know who to trust, all she knows is that she feels like the net is closing and she wishes she'd never heard of the money...