The Sleeper series:
Sleeper 13
Fugitive 13
Imposter 13
The Enemy series:
Dance with the Enemy
Rise of the Enemy
Hunt for the Enemy
The James Ryker series:
The Red Cobra
The Black Hornet
The Silver Wolf
The Green Viper
The White Scorpion
The Dani Stephens series:
The Essence of Evil
The Rules of Murder
Echoes of Guilt
Others:
Dark Fragments