Alexa Lee is the main antagonist from "Infernal Guinea Pig", episode 3.16 of Lucifer.
Alexa Lee is a B-movie producer whose assistant Bree Garland was the victim of an explosion. The explosion occurred at Alexa's home, with a bomb in the mailbox going off while Bree was getting Alexa's mail. Alexa was encountered by Chloe Decker and Dan Espinosa at the scene and responded to any questions by stating that she was at her Pilates class at the time of the explosion, while it was believed that Alexa was the target. Bree was revived due to Lucifer taking the soul of Abel (the brother of Cain, aka Lt. Marcus Pierce; in a plan to remove the curse on Cain), and it was later revealed that the bomb was linked to fertilizer used in Bolivia.
The revelation led to Bree shooting and killing a Bolivian drug cartel member (though she was aiming at Amenadiel); and after this, Alexa was questioned once again by Chloe and Lucifer, who now know that Bree was the true target. She was told about Bree being alive and gave Chloe access to a file containing documents of interactions with the Bolivians, only to learn that Bree's thumbprint can open it. Cash transfers made to Bree's account to the Bolivians drew suspicion towards Bree, but the episode's climax revealed Alexa as the true villainess.
It turned out that Alexa used her movies to launder money to the Bolivian drug cartels, and once Bree found out, the Bolivians attempted to buy her silence. The earlier bombing was in response to Bree still wanting to reveal Alexa's heel persona and her shady dealings, and as for Alexa, she purposely rescheduled her Pilates class that day so she could leave the house before the bomb was delivered. After the second encounter with Chloe revealed that Bree was alive, the evil Alexa planted a bomb in the drawer that contained the documents, doing so in a plan to kill Bree. The villainess also took Bree's belongings out of her hospital room; all the while, Bree, Chloe, and Lucifer discovered the bomb in the drawer. After Chloe diffused the bomb, she revealed to Lucifer that Alexa's prints were found on the bomb, which was enough to arrest Alexa (off-screen) for her crimes.