One thing about all the Marvel shows: When a seemingly minor character starts spouting more lines than expected, they're about to become a larger one. But even so, when the prison guard in charge of Alisa Jones in Jessica Jones Season 2 started making comments about powered people, the first instinct was this was simply to establish that unlike Detective Costa, Jessica was now dealing with prison guards who weren't sympathetic to her. Turns out it was much bigger than that. So who is Dale Holiday? And why did he suddenly become an important (but short-lived) character in Season 2? Warning: Jessica Jones Season 2 spoilers follow.
Let's start from the beginning. It's obvious that once Jessica's mother winds up in jail, a lot of people are going to see her as guilty by association. After all, she kept the woman in her house for two days without telling anyone. And there's the knowledge of "how they like to team up" as Sunday so succinctly put it back in the early episodes. So it would make sense the show would want to establish an adversarial relationship.
But even so, I personally wasn't expecting it to go farther than that. But that's the thing about these 13 episode series: Even though there's not enough story to fill them, they have to find something, and pad things out. That's where Dale comes in.
So Dale can't just be an officer who is bigoted against powered people. He also can't just be one who thinks he's in control and learns a little bit about how strong Alisa really is when she nearly kills him. Instead, he's a sadistic prison guard who was fired from his last job due to "too many prison suicides" under his care.
In short, he's a murdering psychopath, who is worth Jessica killing in a vigilante justice move to save her mother. He's a terrible horrid person who is worth taking out.
While Alisa was in prison, he comes into her cell and starts torturing her, burning her with electricity wired through her chains. He rips up everything she loves and everything she holds dear. And when Jessica breaks into his house, he has a pile of prisoner numbers as trophies. (Note how he calls Alisa by her Prisoner Number as if he's memorizing it, because it's going to mean so much to him later.)
To be fair, the show didn't actually make Jessica's murder of him her fault. He attacks her when he finds her in his house, shouting at her that this murder will be self-defense, she attacked him first, etc. Jessica is actually acting out of self-defense, with her eyes full of pepper spray and her brain half fogged. She forgets how strong he is and a knock on the head with his own club that would have just knocked out anyone else shatters his skull.
As Kilgrave says "he was a sadistic twisted little s*** that deserved it." The show made sure of that, because though this is now "three lives and counting" it's still not actually Jessica's fault any of them died. One thing about the Netflix Marvel shows is even though they make Jessica into a badass is that, at the end of the day, she still has to be a good, likable person who we at home are rooting for.
And it's not like she doesn't pay for it, as Dale's death triggers some hard Kilgrave based PTSD, giving us the one episode cameo of David Tennant we've been waiting for. Dale's dead, mom gets a new guard, we get Kilgrave. Just this once, Jessica, everybody wins.