Mystery or Horror? Bram Stoker's Dracula

Dracula, by Bram Stoker was first published in 1897 when he was 50 years
old. He died in 1912 at the age of 65 (according to onlineliterature.com .

While reading Dracula, I decided it is a good  mystery.

What qualifies it as a mystery? Every genre has the potential to be included in the mystery genre. To qualify as a mystery the story needs certain considerations: A crime, a secret, a detective, suspense and an orderly resolution.

A crime, either the death of Lucy Westener early in the book, or any of the other deaths in the book would qualify. 

A secret---there are plenty of those, even those between Jonathan Harker and his wife Mina who promised never to keep anything from each other. Dr. Seward is the best secret keeper, but the others --each hold something back.

A detective, I think Mina Harker is the best detectives in the book. She is brilliant, and even when under the spell of the monster Count Dracula, she reasons, plots, and delivers the necessary clues.

There are four others (her husband Jonathan), Dr. Seward, Professor Godalming, Mr. Van Helsing, and Arthur Qunicy also plays a part of the detecting crew.Their names intrigue me. The define them.

Suspense, oh yes, there is a whole boatload of suspense here. As to the orderly resolution...
We are taken round trip from Transylvania and back to Transylvania with the original Dracula and his first adversary Jonathan Harker.

Yes, Dracula is a very credible mystery dressed in the clothing of a well plotted horror story. Don't you agree?