She is determined to kill in Murderous Heart_1.

Iris Mitchell could tell that Lyra Smith was losing patience. The grin on her face grew more sinister by the second, "Lyra, don't worry so much. Crime isn't a one-time thing, and anyhow, I'm not brave enough to come after you now."

"Seems like you quite enjoyed your last visit to the police station, didn't you, Iris?" Lyra smirked.

Iris's smile faded a bit, "Well, I have you to thank for that, right?!"

Lyra continued to chuckle, "That's a rather extreme claim. Did I personally put a knife to your throat, forcing you to do whatever you did?" Her laughter deepened, "That wouldn't be the case, right, Iris?!"

Iris's expression hardened.

Cynthia Taylor, a spectator on the sidelines with no input, didn't quite comprehend what the two were discussing.

Their conversation was rather covert.