The Name of the Star by Maureen Johnson

Synopsis (according to the waterstones website)

Sixteen-year-old American girl Rory has just arrived at boarding school in London when a Jack the Ripper copycat-killer begins terrorising the city. All the hallmarks of his infamous murders are frighteningly present, but there are few clues to the killer's identity. "Rippermania" grabs hold of modern-day London, and the police are stumped with few leads and no witnesses. Except one. In an unknown city with few friends to turn to, Rory makes a chilling discovery! Could the copycat murderer really be Jack the Ripper back from the grave?

What I Have to Say

  I really loved reading this book. I've read books by Maureen Johnson before and really enjoyed them, but this is definitely the best so far. The research into Jack the Ripper is really well done and the plot is intricate and enthralling.

It can really be creepy at some points though, especially because most readers have enough of the idea of the plot to know things are much more scary than the characters think (being careful to give away no spoilers).

So if you're looking for YA paranormal fantasy to read or give to a teenager in your family then this is one of the ones I would urge you to get.