She cornered her terrified flatmate and from near point blank range, certainly no more than a metre away, she pulled the trigger.
Over the next four hours or so, she terrorised him, shooting him over and over again, in the head, stomach, abdomen, hip, shoulder and elbow.
During the attack at her Dallington St, Christchurch, home on March 8, she sent several text messages, including to one friend saying she had shot her victim more than 20 times.
And she text another about hearing him scream and wanting to hurt him more.
And today, she was jailed for more than six years by a judge who described her crimes as premeditated and frightening.
The court heard that air rifle pellets have been taken from the victim's abdomen, hip, shoulder joint, three fragments from an elbow joint, and one metallic pellet removed from his skull.
He also underwent surgery to remove part of a pellet from behind his stomach – an invasive procedure that required some 40 staples.
The victim has undergone three surgeries and is left with scarring, restricted movement of his left arm, migraines, and shrapnel left in his face and stomach.
Anderson's lawyer Andrew McKenzie said there had been no violence used in the kidnapping and that while the victim might've been very scared, his life was never in danger.
He told Judge Brian Callaghan that Anderson is now clean of drugs and trying to turn her life around.
She knows her victim did not deserve the treatment she meted out.
Judge Callaghan said it was hard to know exactly how many times the victim had been shot. The victim thinks about 15 times, while Anderson texted a friend to say she'd shot him more than 20 times.
"Clearly there were a number of pellets removed from the victim," the judge said, calling it a "revenge" attack and required a stiff jail term.