My first victim would be a person of a very large stature. Their eating habits could only be described as gluttonous. I would tie the victim to a chair, and force them to eat until I tell them to stop. They could either choose to eat, or get shot in the face with the gun I have, somehow. If they need to vomit, I have a bucket provided. They will continue to eat until I administer a final kick to the stomach, which will burst the victim open, I guess. The police will be baffled as to why this would happen, and who would murder someone in such a horrible fashion. This is only the first. The police don't know it yet, but I have written the word "GLUTTONY" behind the victims refrigerator in grease.
The second would be a very greedy person, one who would do anything, regardless of morals, to get their money. This would include people like lawyers, specifically those who defend criminals like murderers or pedophiles. I will force the victim to chose between being shot in the face, like victim 1, or carving a pound of flesh off his/her own body. When they has made their decision, regardless of what they chooses (tip: both lead to death) I will write "GREED" in the victims blood on the floor. The police, provided they found the gluttony message, will probably assume that there is a serial killer basing his murders on the 7 deadly sins.
I will then lead the police to find the third victim, a convicted criminal who has been waiting for them an entire year. I have prepared in advance, and have strapped this man to a bed, keeping him alive with IVs. I take a picture of him every day, and leave the 365 photos for the police. The man will be hardly alive by the time the police arrive. With his mobility limited, he seems much like a "SLOTH", no? So, I write this on the wall above the victim. They will be a criminal who was defended by victim 2, for dramatic effect. I leave another piece of evidence at the scene,a picture of the next victim, who is a prostitute.
You can probably guess where this is going. Since the victim is a prostitute, she obviously engages in excessive sex. I will not commit this murder myself. Instead, I will force a man to wear a contraption I order at a specialty sex shop, which is basically a strap on dildo with a knife on the end. The prostitute will be bound, and the male victim will be forced to wear the sex-knife and engage in intercourse with the other victim. Once this is done, I will write "LUST" on the wall in the victims blood. Since this location has a lot of "customers" and their "toys" coming in and out of this establishment, the owner will not be able to point me out.
The next victim will be a person who values their appearance and self above all else. Somebody superficial, like a model. I will cut off the victims nose, and gave her the choice of suicide by sleeping pills, or calling police for help, and living scarred. Without her image, a model is nothing. Regardless of the choice she was going to make, I cut the phone line just to be a dick. I write "PRIDE" in the victims blood above the bed, where I will leave her bound with the phone and pills.
At this point, I will realize I might just be Kevin Spacey. Scared, I cut off my fingertips, and turn myself into the authorities.
I will then force Brad Pitt to shoot me out of "WRATH", since it turns out I became the embodiment of "ENVY".