When it comes to books in 2012, it was all about mystery thrillers -- particularly by Scandanavian authors.
West Chester Public Library director Victoria Dow said that's because of a trend started by "The Girl With the Dragon Tattoo."
"The mystery thriller kind of genre books...are the ones that generally circulate the most," she said. "It doesn't surprise me that that type of book is [popular]."
Dow said that all the books on West Chester's most circulated top 10 are available at the library, as well as at other branches.
1. "As a Pig Turns" by M.C. Beaton
Checked out a grand total of 27 times -- each with a one-week checkout period -- this mystery thriller was West Chester's most popular of 2012.
The book is an installment of a series that takes place in a village that throws a beginning-of-winter pig roast. When the roast is discovered to be the body of a less-than-popular police officer, an investigation is launched. Agatha Raisin, a local, decides to solve the mystery on her own.
2. "Down the Darkest Road" by Tami Hoag
The disappearance of Lauren Lawton's 16-year-old daughter has gone unsolved for four years. After her husband commits suicide from grief and everyone gives Lawton's daughter up for dead, Lawton knows who did it. But she has troubles getting help from the police and must rely on doing something herself.
3. "The Affair: a Reacher Novel" by Lee Child
Jack Reacher, a military cop, is ordered to investigate the death of a young woman near a military base in Mississippi. Reacher and the local sherriff pair up to solve the murder -- but are unsure if they can trust each other.
4. "Calico Joe" by John Grisham
Taking place in the 1970s, Joe Castle, known as Calico Joe, is the time's baseball star. When Castle meets his match in a Mets pitcher, he hits a foul ball that involves the pitcher's son and changes the three of their lives forever.
5. "1222: a Hanna Wilhelmsen Novel" by Anne Holt
After a train en route to northern Norway derails during a blizard, riders take shelter in a nearby hotel. Just when those evacuated from the train think they're safe, one of them is killed. Paralized, retired police officer Hanna Wilhelmsen is asked to investigate. Another person is killed and everyone panics. With the storm raging on, Wilhelmsen is the only one who can solve this case.
6. "Explosives Eighteen" by Janet Evanovich
Bounty hunter Stephanie Plum is on a flight from Hawaii to Newark. But during a layover in Los Angeles, her seatmate turns up dead. This launches an FBI investigation that ends up complicated.
7. "The Boy in the Suitcase" by Lene Kaaberbol
Nina Borg's estranged friend leaves her a key to a public locker. In the locker, Borg finds a boy -- naked and drugged -- in a suitcase. After Borg's friend is discovered brutally murdered, she realizes her and the boy's lives are in danger.
8. "City of Whispers" by Marcia Muller
When private eye Sharon McCone gets an email from her brother asking for help, she replies and doesn't get an answer. When she looks into it, she realizes the email was sent from a cafe in San Francisco, somewhere her brother's never been. She quickly begins to wonder whether he's in serious trouble.
9. "Zero Day" by David Balbacci
John Puller, a top-notch military investigator, is sent to investigate a burtal West Virginia murder of an entire family. Through his investigation he learns that nothing is as it seems.
10. "Heat Rises" by Richard Castle
Nikki Heat, a New York City homicide detective, finds herself investigating the murder of a parish priest. She finds herself in a conspiracy and is not only stripped of her badge, but the target of the murderer.