Dear, let me answer

Based on the clues you provided, I think you may be describing a domestic drama called "Black Hole". This drama was directed by director Guan Hu and starred by actors such as Tao Zeru and Chen Daoming. It premiered in 2001.

"Black Hole" mainly describes the investigation team leader Liu Zhenhan who accidentally discovered a secret related to the "black hole" while investigating a murder case. This secret is inextricably linked to a deputy mayor named Nie Mingyu. contact. In the play, Nie Mingyu is an upright person on the surface, but in fact he has many secrets.

The plot of the case you described is somewhat similar to that of this drama, especially the plot of using a hammer to kill people. As for the percussion and rock-style background music you mentioned, as well as the wrinkled picture feel, these clues are also consistent with the style of the drama "Black Hole".

"The True Colors of a Detective" is also possible. This drama is also a TV drama with criminal investigation as the main line, and each episode revolves around a case. At the same time, it was also broadcast around 2000, which is consistent with your memory time.

"Black Hole" is more likely. I hope it can help you. The answer is not easy. I look forward to accepting my answer. Thank you very much~