Although the plot appears to allude to Korea's real-life Hwaseong serial murders case, the series is a work of fiction and its similarities are explained by inspiration drawn from Bong Joon-ho's film Memories of Murder (2003).

Shin Ha-kyun and Yeo Jin-goo, who play the two lead detectives, had previously worked together on the film No Mercy for the Rude (2006), in which Yeo Jin-goo played the younger version of Shin Ha-kyun's character.

Lee Do-hyun appears in a special guest role playing the teenage version of Lee Dong-sik, the lead character portrayed by Shin Ha-kyun, twenty years in the past.

Beyond Evil received seven nominations at the 57th Baeksang Arts Awards and won three, including Best Drama, Best Screenplay, and Best Actor for Shin Ha-kyun; it was also a final candidate for the Baeksang Arts Award Grand Prize – Television.

The series was later confirmed to be getting a Japanese drama remake, though no broadcaster or airing date had been publicly announced at the time.