Adam Goldberg addressed Harry’s motivation when he “discovers that his mother was troubled” and that she didn’t leave him because “she didn't love him and she didn't abandon him.”

Source: https://www.cinemablend.com/interviews/after-the-equalizer-addressed-antisemitic-hate-star-adam-goldberg-and-writers-break-down-harrys-message-to-the-attackers-and-powerful-final-scene

McCall's team includes Mel Bayani (Liza Lapira), a bar owner with a past as a military sniper, and Harry Keshegian (Adam Goldberg), a white-hat hacker with a paranoid streak.

Source: https://screenrant.com/the-equalizer-season-3-lorraine-toussaint-clip/