Silent scream - Karen Rose

She was in the wrong place at the wrong time: in SILENT SCREAM, the brilliant novel from the bestselling Karen Rose, arson leads to murder and blackmail, and David Hunter, who first appeared in DON'T TELL, leads a desperate search for those responsible. Part of the Minneapolis series.

Four college kids set fire to a supposedly empty condominium block. But when they see the young girl at an upper-floor window desperately banging on the glass, clawing to get out, they realise their mistake. Although they don't all agree, the group leave the girl to her certain death, little realising that someone is there, watching their every move. Someone who has a nasty habit of blackmail and sees an opportunity for profit which is far greater than any they have ever had before.
For local fire fighter David Hunter, getting the blaze under control is hard enough, but when he finds the girl's body he realises that this arson attack has become a murder case and the homicide cops are immediately called in. Now, as David works with the cops, it's a race to find the arsonists, and the blackmailer, before events escalate out of all control.