A star of The Walking Dead has been cast as the lead in the new CBS All Access series, according to EW.  Sonequa Martin-Green, who plays Sasha Williams on The Walking Dead, will play a lieutenant commander on the Discovery, according to the report.  The role of the lead is a departure, as all past Star Trek series have focused on the captain of the ship. 

Martin-Green will continue to appear on The Walking Dead as well, according to the report. 

Casting has been ongoing.  Anthony Rapp will play Lt. Stamets, a gay astromycologist, and Doug Jones will play a science officer from a new alien species (see “’Star Trek: Discovery’ in Geek TV Round-Up”).  Michelle Yeoh was cast in a recurring role as a starship captain (see “Michelle Yeoh Cast in ‘Star Trek:  Discovery’”).