He is one of several detectives in the Miami Metro Homicide Department.
Mostly he acts in the background, following orders to investigate crime scenes and is around in times of emotional turmoil for the whole department: such as when Angel Batista was attacked by the Ice Truck Killer and in Season Three when Vince Masuka stood up to Lieutenant Ramon Prado of the Sheriff's department. He was also present during Dexter and Rita's wedding, smoking a cigar with Joey Quinn and several other detectives.
Detective Michael Soderquist first appeared in Season One and has appeared in almost every episode of the show since then, along with partner adjacent, Detective Israel Yale. Soderquist is highly visible in his signature "ice cream" colored polo shirts.
- His first name is revealed on a nameplate only present after "Resistance Is Futile". Following the department's restructuring in Season Three, the nameplate is no longer there. Interestingly, there is no indication on why the nameplate appears so late in Season Two as it is not present at the desk before then. Another oddity is that Soderquist is never seen sitting at this desk though it has been used by Maria LaGuerta, Detective Hill and Robert Ramos.
- In "Easy as Pie," Dexter creates a list of who he is inviting to his wedding. He considers the detectives Soderquist and Robert Ramos, but Dexter doesn't remember his name. Once Angel Batista orders them both to keep surveillance on Anton Briggs, Dexter says the following, "THAT'S his name...Soderquist."
- Michael Soderquist is one of few background Detectives that have existed prominently since Season One. Other Detectives include Detective Hill and Detective Israel Yale.
- The actor, Bruce Holman, has also played a background Detective on the USA TV Series Monk. He can be seen briefly in the second episode of the fourth season behind Captain Leland Stottlemeyer before a scene transition.
- He is the first of a series of recurring background characters to appear, though he's only barely seen sitting at one of the Detective desks in "Crocodile" while Debra is telling her brother about Sean the Mechanic.
- His name indicates Swedish ancestry, "Soderquist" is the Anglo-Saxon form of the Swedish "Söderquist" (roughly translating to "south twig")