Belated Witness - Watchbearers, #6

It's never too late to uncover the truth. In a Seattle suburb in the summer of 1989, someone saw a woman pushed out a window and plummet to her death. Unable to identify the killer, the witness chose not to come forward. And Dorothy 'Ace' O'Reilly's death was written off as an accident, the murderer never brought to justice. But when time-traveling sleuths Sam and Bailey are asked to investigate, they can change the rules and discover what really happened.
And in the process put more lives at risk. This is the second Sam and Bailey mystery. The first is Uncertain Murder, but their story starts in Watchbearers Book 1: Millennium Crash. And their next adventure after Belated Witness is in Book 5: Temporal Entanglement. That's time travel.