Assassin.

She walks in shadows.
Slow, calm and silent.
She moves with patience,
Stalks her prey.

Shadowing her kill,
Stalker for the rich,
She loads her gun,
Slides it into view.

Shoots her target,
Slays her prey,
Shadowing the police,
She hides again..

Slayer,
Stalker,
Shadow,
She is a hired killer.