Deceitfulness is characteristic of personality disorders. The affected person works at disguising their affliction, which necessarily involves deceitfulness.

The disposition to deceive; as, a man's deceitfulness may be habitual., The quality of being deceitful; as, the deceitfulness of a man's practices., Tendency to mislead or deceive.

deceitfulness, dishonesty, untruthfulness, falsification

Dolosity is said to mean deceitfulness or hidden malice.

He couldn't tell the superintendent who the first two disciples were.