While Grijpstra was portrayed as a family man with several children in the original novels, the show portrayed him as having a quite dysfunctional marriage, later also mentioning a son living on the streets as a heroin addict.
13 episodes were shot for the 1st season (2004), but the last four were not aired; instead four Baantjer (1995) episodes were aired in their slots. The remaining four episodes were aired in the 2nd season (2005).
All scenes at Fred's café for the entire season (there is usually one per episode) are filmed in an actual café simultaneously. The shooting only takes a few days.
Due to budget constraints at RTL4, the fourth season was moved from spring to fall 2006.
The show was originally conceived as a replacement for 'Baantjer (1995)', RTL4's popular Friday night crime series. The shows share quite some similarities: both were aired at Friday night om 8:30 PM, both featured a male detective duo in a fairly formulaic, case-of-the-week format, both were based on popular crime novels which had previously been adapted into a feature film: in Baantjer's case, 'Moord in extase (1984)', in Grijpstra & de Gier's case 'Grijpstra en de Gier (1979)' and 'De ratelrat (1987)'. However, the show ended up mostly existing concurrently with Baantjer, which lasted until 2006. Grijpstra & De Gier lasted only a year longer, ending its run in fall 2007.