"The Name of the Star" by Maureen Johnson

Warning: Will Contain Spoilers

So here's how this works: I say the name of the book, who it's by, then I list spoilers that may or may not ruin the book for you. If the book has sequels, well, you need to wait until the post on those books becomes available.

"The Name of the Star" by Maureen Johnson

Rory chokes on a piece of meat and then can suddenly see ghosts.

Alistair is dead.

Jazza doesn't die.

Jerome and Rory do end up making out.

The hot young police officer, Stephen, is a real cop but he's part of a ghost-seeing section that consists of three people.

Boo is a cop, too. 

The old phone Boo carries is actually a tool used to "kill" or erase ghosts called a terminus.

Stephen can see ghosts because he attempted suicide. Callum can see them because he was electrocuted. Boo can see them because she was in a car crash.

The Ripper is a ghost named Newman who was part of the old ghost-seeing cop division when he was alive. He murdered everyone else in the division and then killed himself.

Newman could see ghosts.

Stephen is shot up with insulin by Newman. Callum and Rory hand over their termini, which are subsequently destroyed, in order to convince Newman to save him.

Charlotte doesn't die.

Rory gets stabbed by Newman. She doesn't die, either.

Newman dies and so does Jo.

All three termini are destroyed.

Rory signs a nondisclosure agreement and is sent away to live with her parents.

Rory is now a terminus and kills ghosts with her touch.