Among the more common profiles of those of airplane hijackers, drug couriers, arsonists, serial murderers, abusive spouses, and abusive parents. Traditional syndromes include battered women, battered children, rape trauma, and child sexual abuse accommodation syndrome. Some of the more exotic syndromes include Vietnam Veteran's, pathological gambler, urban rage, Superbowl Sunday, and sexual addiction syndrome. Airline security personnel, customs agents, immigration officials, and law enforcement personnel use profiles, particularly for hunting serial killers or serial rapists. Profile evidence is generally not admissible in court proceedings to prove guilt, although it is sometimes admitted for narrower purposes. The first hurdle to admitting syndrome evidence in criminal trials is determining whether it is a form of science and, if so, whether it can meet the applicable standards for the admission of scientific evidence. Courts are most negative toward evidence offered by the prosecution that a defendant satisfies a particular syndrome. Courts are more receptive to syndrome evidence offered by defendants. Courts are even more accepting of syndrome evidence to change attitudes toward a witness who has been impeached on grounds that lend themselves to misunderstanding. Continuing scientifically controlled research and increased judicial scrutiny may enable profile and syndrome evidence to expand their potential for aiding investigations and trials without undermining fairness or diluting standards of criminal responsibility. Footnotes and 7 references