Top Secret: The Revelation

Only Himitsu springs to mind when thinking of other sci-fi 'investigation team' series involving the usage of futuristic scanning technology that reveals the truths people try to hide from others. In Psycho-Pass technology exists that can display a number for each person, revealing if people are "latent criminals" or not. In essence, it's technology that allows for the punishment of thought crime. In Himitsu the last memories of those murdered can be viewed in order to catch the criminals responsible. It's very similar to how in Minority Report the pieces of visions would be put together in an attempt to solve crimes... only after the crime is committed, rather than before. Both series begin with a rookie cop just starting at their new jobs and having to balance the practical realities against the moral weight of their actions. Then, until the last stretches of the two (/end of series arcing), it's episodic psychopath hunting. read more 

Both shows are thematically dark. The murders in both have heavy psychological components. The investigators have similarities. 

Another low-budget detective series.  

Both series focus on psychological issues, crime, and motivation. An eccentric yet brilliant detective also figures prominently in both anime. 

-About detectives and police who solves murder mysteries, and must deal with the living, as well as the memories of the dead. -Each has two main characters: one has a secretive and acidic personality, and the other wants to figure out what burdens he carries to make him that way. -Has something to spice up a plain mystery storyline (Shinrei has supernatural elements, and Himitsu has sci-fi) -Both have a lot of horror and creepiness. Himitsu is a LOT more gory (but I think it's the more interesting of the two). 

Both series revolve around a newbie cop working with a special police unit which deals with unusual cases in not exactly conventional ways, and that would be the only similarity since the plots are utterly different, however "Himitsu" is undeniably better of the two. 

Several characters spend the whole show trying to solve mysteries in a world filled with conspiracy.  

Both series have sci-fi technology that helps the police solve mysteries through diving into minds/memories, which has immense consequences for the investigators and the world around them.  

Both of them deal with interesting and controversial psychological issues. Both are also very good mystery anime with good development of story and character.  

Both animes deal with the mysteries of human brain, both have an intellectual feeling and demonstrate how dark and cruel humans can be. Also, in both animes the main characters are two males (brothers in Night Head Genesis and a boss and an employee in Himitsu). 

Both animes contain a series of detective mysteries the characters have to solve. In Himitsu it is done through looking into a dead person's brain, in Ayatsuri Sakon the mysteries are solved by a young puppet-master using his doll for it. Both animes explore the dark corners of human souls.