I write crime fiction because I like the psychology behind killers and what makes them tick, and the detectives that chase after them. I like trying to figure out what motivates someone to kill, and how they plan it out.

When I sit down to write a new crime thriller, the first thing I do is figure out why my killer is killing. It could be for any reason, but I need a reason. For me, the murders dictate so many other aspects of the story.

The second thing I do is figure out my victimology. I need to know why my killer chooses his/her victim(s).

By figuring out those two things, I can then outline those characters. By developing my killer’s psyche and why he kills, and my victimology, it helps me create more in-depth characters.

How do you do figure out why your killer is setting out on his murderous spree? Look at some things that motivate someone to kill. From the most mundane trigger to some kind of deep-rooted psychological problem.

Here are just a few things I may consider when I'm trying to figure out why my character is killing:

Emotional State

Is your killer driven by his emotions? Look at any criminal case, and you will see a host of emotions that drove a person to kill. Emotions play such an integral part in why someone kills. Especially if they have a problem with control. When I think of emotions that would make me kill, jealousy is a big one. However, other emotions can be a trigger too.

Physical Ailment

Maybe your killer has a deformity or even something as small as a stutter. That inadequacy could drive him to murder certain people because they teased him, or he wants them to suffer as he does.

Maybe he kills because someone he loves or loved had a deformity caused by someone else.

Trauma

Did your character suffer some sort of trauma that he or she now seeks revenge against those, or a substitute for those that hurt him/her? Like, for instance, a woman who was raped at a college party by a young man or several men.

Maybe something triggers her, and she is killing men of that same look or personality or other college men. Perhaps she is even going after the same people who hurt her in her past.

You can take something like a victim of a violent crime and have them kill violent offenders in their neighborhood. All good vigilante movies and books are based on this premise.

Obsessive stalker

These are great characters to work with. You can make their obsession overt or completely psychological. If they are overt in their stalking, they may send text message after text message, a barrage of phone calls to their intended love interest. Always send them gifts or flowers. Or maybe they show up at the same venue as their soon to be victim.

If the person doesn’t give them the response they want, or they give their affection to others, that killer may choose to kill the other people in that person's life...you know--if I can't have you, no one else can.

Or if they are more psychological in their obsession, they do things that to the average onlooker seem harmless, or even nice. When the victim tries to show what the person is doing to them, it only makes them look crazier, not like a perpetrator. Thus, your killer takes great pleasure in their intended victim’s discomfort. And that all leads up to their death, or again the death of people around them.

The second part in developing my killer character is the victimology of his victims.

Say, for instance, I am using a young girl who was gang-raped at a college frat party. She is now in her mid-twenties and sees that the boys who drugged and raped her are all very wealthy and famous. That triggers her to kill them.

But she isn’t going to kill each man the same way--each of the men played a specific role in her attack. Maybe one man held her down but didn’t rape her. Perhaps one was even a girl who pretended to be her friend and lured her to the party. Maybe one was the ringleader and told everyone else what to do.

She would want to kill them differently. Her level of anger, hatred, or resentment would be different towards each perpetrator. She may even have sympathy for one man.

I could write these victims in such a way that my reader would sympathize with my killer and would root for her to kill them. Or I could write these victims in such a way that may make the reader sympathize with the victim and not the killer. (They are still going to die, bwahaha).

Look at Dexter. He worked in the criminal justice system and killed criminals…or those he perceived to be bad. Of course, Dexter was fucked, he suffered severe trauma and used that trauma later to kill. And we, or at least me, rooted for him. I loved Dexter. I wanted him to kill his next victim. I often thought if I could be Dexter, I would….No, I will not start killing people, (I don’t look good in prison orange) but that character was likable, even though he was doing a heinous act.

You want your killer character to be liked or hated...you definitely don’t want a killer that makes your reader go “Meh.” That is the kiss of death for a character.

You want to evoke a response from your reader, without pushing them too far. An example of that would be your bad guy kills a dog. Lots of readers hate that and may not like you as an author anymore. It’s okay to kill a dog, but you have to have a good reason for killing the dog. Don’t just do it for shock value and no purpose. That can be unforgivable to the reader.

I like to do things that make my reader cringe. I want them to be uncomfortable. But not just for the sole purpose of doing it, I always have a reason behind it.

I hope this post helps you create your killer character.