Class of Lies

if you liked Tell me what you saw i am sure you gonna like Class of lies too, that's my opinion.
Class of lies is about a highly successful lawyer who falls from grace because of one case. He becomes a fixed term teacher at a high school that is tied to that case in order to regain his honor. Though he goes into the classroom for selfish reasons, he begins to see the crimes that take place and he takes matters into his own hands to help protect victims from their peers. The drama will shine a spotlight on the reality of teenagers facing little to no repercussions after committing a crime because they are teenagers, providing no protection for those who become a victim to these crimes. (Source: Soompi)
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Tell me what you saw is about Oh Hyun Jae who used to be a top criminal profiler. He solved many cases with his skills, but one day an explosion, caused by a serial killer, ended the life of his fiancé. After the horrific incident, Oh Hyun Jae vanished and he now lives in seclusion. Meanwhile, Cha Soo Young is a police officer in the countryside. She has a special ability which allows her to remember exactly everything she sees. Due to her special ability, she is selected as a rookie detective who will partner with Oh Hyun Jae informally. Together they work to solve cases and uncover the truth behind the Peppermint Killer, the resurfaced serial killer who murdered Hyun-Jae's fiancé five years ago.
(Source: AsianWiki)

they both have that "do anything for specs" thing.. but Class of Lies is more focused on the students

similar in this two drama- the main male lead is a Prosecutor,
Investigation,
hacker,
find out the truth,
some people want to take revenge,
so much corruption,
people don't get proper right,
cover some wrong doing,

Kim Yeon-hong (Son Ye-jin)appears to have a perfect life. She is beautiful, is married to a charismatic young politician (Kim Joo-hyuk), and her adolescent daughter who used to be a troublesome child is now doing better at school. Her husband, Kim Jong-chan decides to run for office against the powerful incumbent, No Jae-soon (Kim Eui-sung). A few days before the elections, Yeon-hong and Jong-chan's daughter, Kim Min-jin (Shin Ji-hoon) goes missing. At first, they assume she has run off to seek their attention as she had done before. However, Yeon-hong soon finds out that the friend Min-jin said she was going to meet does not exist. Then Yeon-hong learns from the school her daughter attends that she had an eccentric friend named Choi Mi-ok (Kim So-hee [ko]) and they were both bullied by their classmates.

Junior high school teacher Yuko Moriguchi (Takako Matsu) announces to her class that she will resign before spring break. Moriguchi reveals that because the HIV-positive biological father of her daughter Manami was ill, she used to bring Manami (Mana Ashida) to school with her. One day, after school, she returned to the room where Manami was but found her gone. Her daughter was later found drowned in a school swimming pool. She then explains that two pupils in her class, whom she dubs "Student A" and "Student B", have murdered her four-year-old daughter.

Both Class of Lies and GTO series are about a teacher that is different from the other teachers in the school. They make a difference in a class of troubled students, providing a unique perspective and a much needed adult figure in their lives.