If a vampire does not kill the victim but instead turns them into a vampire is this illegal?
Illinois has had a law in the books since the late eighties that makes the knowing transmission of HIV a crime. Although, the vampire transmits his curse through the blood, no state has yet passed a law similar to the HIV statute related to vampires. I suspect this has to do with the large number of vampires who are elected members of the legislative branch of state and federal government. I should also note the impact of the well funded and powerful vampire lobby groups.
In addition those in the House and Senate of the werewolf persuasion are likely to vote against any legislation perceived as anti-vampire. Historically they are concerned that a similar statute could impact them in the future. I should note in the early 80's that both Republican and Democratic lycanthropes voted against funding for research involving miniature suns as a source of energy production. They did so out of respect for vampiric concerns.
Does this mean the vampires are free to act as they like? The answer is no. Battery is an unwanted touching. Under Illinois criminal law, "A person commits battery if he intentionally or knowingly without legal justification and by any means, causes bodily harm to an individual or makes physical contact of an insulting or provoking nature with an an individual." 720 ILCS 5/12-3. A battery can be charged criminally in the form of a misdemeanor battery (720 ILCS 5/12-3) or a felony battery (720 ILCS 5/12-4). Battery can also result in a civil suit. Meaning a vampire can be sued for monetary damages. If a person is killed in relation to a vampire attack the vampire can even be charged with murder (720 ILCS 5/9-1). A life sentence to a vampire is substantially longer then the same sentence to a human being and is thus a serious deterrent.
In 2002 The United States Supreme Court rejected the necessity defense as it relates to the undead in the case of Illinois v. Tepes. Illinois v. Tepes, 666 U.S. 327 (U.S. Supreme 2002). In that case the vampire argued he would die if he did not feed and thus his actions were necessary for survival. The majority opinion with Vlad Dracul as the sole justice in decent stated that a person or vampire can not choose one life for another. The Court further points to the possibility of feeding on animal blood or going to a blood bank. In the Illinois case of People v. Nosferatu, two arguments were made as affirmative defenses to a murder charge. The first was akin to an insanity defense alleging that the "blood lust" made the vampire unable to control his actions. The second argument was that the "blood lust" negated the ability for the vampire to act rationally and thus negated the "mental state" or "mens rea" that was a prerequisite to conviction of the crime. These arguments were rejected by the court. People v. Nosferatu, 232 Ill. Dec. 744, 623 N.E, 2d 666 (4th Dist. IL. 2003) Justice White speaking for the majority states, "Experts for the defense were able to establish the existence of the 'blood lust'. That being said there was no evidence this 'blood lust' was any different then a drug addicts desire for cocaine. To except this argument would open the flood gates to all addicts to justify any crime no matter how heinous." People v. Nosferatu, 232 Ill. Dec. 744 at 750, 623 N.E. 2d. 666 at 700 (4th Dist. Ill. 2003)
Thus, a vampire may be subject to both criminal and civil liability for battery. The courts have consistently found blood sucking to be an unwanted touching. Further, flying or floating through windows may result in a conviction for home invasion and/or residential burglary.
Potential Slayer Liability
The next issue relates to vampire slaying. In the landmark case of United States vs. Buffy S., the court held that slaying was not murder because the victim was not alive. United States vs. Buffy S., 23 U.S. 872 (U.S. Supreme 2007). As of yet I have not read any published cases relating to civil liability from the families of slain vampires.
In conclusion, the law is certainly not settled in regards to all aspects of this field. Garlic and/or a religious symbol may provide better protection overall then seeking protection from the courts. That being said I'm willing to make appointments in the evening if the sunlight would prevent your coming in for a free consultation.