For his last few roles, Park Hae Jin chose characters that act bad but who are not really bad guys. He was Jun Ji Hyun's would-be-suitor in "You Who Came From The Stars" and while he indulged in some bad behavior, it was all motivated by his love for the charming Hallyu star.

In "Doctor Stranger," he is out to destroy a man and the hospital he runs, but the revenge he seeks is motivated by an injustice done to his family.

And while it was tempting to think that his character was bad to the core, he winds up doing the right thing in the end.

His next role is in the 11-episode drama "Bad Guys." It's the story of a detective who assembles a team of dangerous criminals. He figures that their knowledge of crime will help him catch even more dangerous criminals.

Park Hae Jin's character in this drama will not only be bad. He will be a psychopath.

According to his agency, WM Entertainment, Park will play the role of Lee Jung Moon, a genius psychopath.

He is different from other psychopaths in dramas because he is so smart. He is the youngest member of Mensa and has an IQ of 160. Having doctorate degrees in math and philosophy helps the character to literally get away with murder.

His youthful innocence has helped earn him the title of "the youngest serial killer."

When asked why he would take on such a role, the actor told enewsworld that he liked the script as soon as he saw, it.

"Isn't it a role any actor would want to try at least once? He's not just a genius psychopath but a character with dynamic aspects."

The writer created the script with Park Hae Jin in mind. Both the writer and director worked hard to convince him to take the role. But even after he agreed, the actor had to fit it into his busy schedule.

"I tend to choose projects after looking at the character but as soon as I saw the scripts, I felt like 'This is it.'"

Park Hae Jin accepted the role before he began filming "You Who Came From The Stars" but "Bad Guys" production could not begin until the actor finished filming "Doctor Stranger," which aired its final episode on July 8.

Actors Kim Sang Joong and Jo Dong Hyuk have also been cast in the drama, which is scheduled to air in October