Fantasy-mystery/paranormal unfinished book series with ghosts as major plot point

I'm trying to find a book series that I read around 3-4 years ago, about a group of friends who deal with ghosts and are trying to fight a villain who has some kind of a weapon that could harm the spirit and human worlds.

About the Series:

Romance + About the Friend Group:

Setting:

Plot:

If any of the details don't quite match with a story that you found let me know, I might just be misremembering it.

This is the Shades of London series by Maureen Johnson.

The plot of the first book involves the 17-year-old protagonist, Aurora "Rory" Deveaux, moving from Louisiana to London to attend Wexford boarding school around the same time that a series of murders breaks out:

Louisiana teenager Rory Deveaux arrives in London to start a new life at boarding school just as a series of brutal murders mimicking the horrific Jack the Ripper killing spree of more than a century ago has broken out across the city. The police are left with few leads and no witnesses. Except one. Rory spotted the man believed to be the prime suspect. But she is the only one who saw him - the only one who can see him. And now Rory has become his next target...unless she can tap her previously unknown abilities to turn the tables.



According to her page at the Shades of London Wiki, Rory develops the Sight (an ability to see ghosts) as well as the ability to vaporise them on contact.

After choking on a piece of beef when telling a story to her friends, Rory unknowingly develops the Sight. Though it remains a latent and unknown talent to her for some time, the first time the Sight is of use to her is when she is at the Flowers and Archers pub, where the police examine the murder scene of Fiona Chapman. Her ability to see ghosts occasionally makes her come across as a little eccentric to her fellow classmates.

Rory starts dating a prefect named Jerome Croft in the first book but they break up in the second.

Jerome is a prefect at Wexford boarding school. He lives in the Aldshot dormitories on campus, and is the former love interest of Rory.

Rory meets a 19-year-old police officer named Stephen Dene in the first book and they share a kiss in the second, near the end of which he dies. She then brings him back to life in the third book, after which they become romantically involved.

Stephen Dorian Dene is the head of the Secret Police who is tasked with dealing with the ghosts in the London area. Aurora Deveaux first meets him after Wexford becomes the centre of police activity, following a murder on the school premises. As of The Madness Underneath, Stephen is Rory's current love interest.

An untitled fourth book was announced and set to be published in 2018, but failed to materialise.

A title for the fourth and final instalment in the Shades of London book series has not yet been revealed. Series author Maureen Johnson announced this final Shades novel on her official website and on her personal Twitter account. Johnson announced that the fourth instalment was expected to be published sometime in 2018, but it did not materialise.

You can view a preview of the first book here.