Alex Blake

Dr. Alex Blake is a seasoned FBI linguistics expert and professor at Georgetown who joins the BAU during the premiere episode of Season Eight after Emily Prentiss left the BAU for a post at Interpol.

Background
Not much is known yet about Blake's private life previous to her incorporation to the BAU except that she is married to a member of Doctors Without Borders, James, who is currently abroad, making said relationship a Skype one.

Blake is a Berkley graduate with a double major. Recruited by the Bureau when she was only 24, she is a veteran FBI agent who made a name for herself by helping solve the Unabomber case, but has a rocky history with Strauss stemming from the Amerithrax case (the investigation of the post-9/11 anthrax attacks) in which Strauss let Blake take the blame when things went south over a linguistics flub and the wrong suspect was arrested. In fact, having been with the FBI since she was 24, Hotch and Rossi too have known her from her career in the Bureau.

At Georgetown, she teaches forensic linguistics to students that are apparently as intelligent as Spencer Reid. She and Reid have some history together since he makes appearances as a guest-lecturer in her classes.

Personality
To be added

Season Eight
In The Silencer, Blake resumes work with the BAU, specifically the team headed by Hotch and Rossi, helping them investigate a serial killer in Seattle, Washington, who was using his son to lure in his victims and, according to her, "made Ridgway look like a saint". Upon returning from Seattle, she meets Morgan and Garcia, who had just returned from their visit to Prentiss in England, and the latter has an embarrassing introductory moment with Blake. Blake then assists the team in their investigation of an escaped convict revealed to be the infamous serial killer "The Silencer". She and Reid work together in trying to deduce a meaning behind messages left behind by the unsub, and when the Silencer is properly identified and tracked down, Blake attempts to talk him down, communicating with him via sign language, as he is deaf. Her attempt to reach him is unsuccessful and he commits suicide. At the end of the episode, Blake and Garcia meet up and redo their introductions, starting a friendship.

In God Complex, she notices that Reid is acting strangely, and when he asks her to drop him off at a payphone, she does so and then asks him what is going on. Reid promptly tells her that he has started calling a woman named Maeve Donovan in a potential romantic relationship, and that he did not wish to tell this to anyone else. Blake promises not to tell anyone. By the end of the episode, Morgan tells Reid that he knows his secret, but from Garcia. Reid then thanks Blake while she is still sleeping. In The Good Earth, Blake assists in the current investigation and is able to successfully talk down the delusional unsub, allowing for an arrest. In Magnum Opus, she is able to deduce the motivation behind the unsub's killings and particularly embraces Reid's return to the BAU after a brief leave following Maeve's death.

In #6, her husband, James, will appear.