Crime Digging-Brother is a Manga/Manhwa/Manhua in english language, Crime series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.nl fastest updating comic site. The Summary is

Jiang Peng, a prison guard, was suspended from pay, when a yellow porn magazine was confiscated from prison. The prisoner hanged himself. The yellow magazine contained a notebook full of unrecognized criminal records. Based on these criminal records, Jiang Peng made a visit and uncovered one by one