The original cast featured Johannes Brandrup as Frank Stolte and Rainer Strecker as Ingo Fischer. Fischer left the series just two episodes later and his replacement became Erdogan Atalay as Semir Gerkhan.

Brandrup quit the series at the end of Season 1. The television netwok RTL, which carries the series, contracted Mark Keller as André Fux in his place. Keller left the series at the end of Season 6 and was replaced by René Steinke as Tom Kranich. He played the role between the seasons 7-14, then decided to quit to try other roles.

Atalay's new partner became Christian Oliver as Jan Richter in Seasons 14-16. When he left the series to build his career in the US, RTL turned to Steinke, who agreed to return at the beginning of Season 17. However, Steinke decided not to renew his contract, and left the series again at the end at Season 20.
His replacement is actor Gedeon Burkhard as Chris Ritter. Burkhard is best known for his role in another German police show, Kommissar Rex.

In 2008 Burkhard is replaced by Tom Beck.



Semir is the main character and one of the cops who stayed on the force from the beginning to the end. He is best known for driving his silver BMW 3 series undercover car throughout his career. He also owns numerous exotic cars outside of work but had terrible things happen to them. (BMW crashed, Ferrari 355 spyder stolen). He is serious and will do whatever it takes to get the job done.

Tom is one of the more outgoing guys on the force, while Semir is serious. Together both of them gets the job done properly, sort of. He also have a forgiving personality due to the fact that he forgave a female driver despite that she wrecked his mountain bike on his first day commute to work. He also owns a Mercedes-Benz CLK 320 coupe, which is wrecked a dozen times.

Chris, who was originally a backup officer for Semir and Tom, became Semir's partner after Tom died in the episode "Auf Leben Und Tod". With the new partner the adventure continues, Chris drives a blue Mercedes-Benz CLK 320 which is the same one as Tom and in season 23 he started driving a gray Mercedes-Benz C350. His off work car is unknown.

Dida serves as the cobra team's backup officer throughout his career, his partner is an obese, bearded german, whose name is unknown. They drive a green and white "Polizei" porsche 911 turbo highway patrol car.

Jan was Semir's partner before he left the force, he was introduced in the episode "Feuertaufe" shortly after Tom's emotional withdraw. He is cowardly at first, even too scared to make a proper lane change. But he later got the hang of it and brings semir out of many dangerous situations. He left the force shortly after and semir was forced to look for Tom again. Tom agreed to go back and he was killed in action shortly after.