Dr. Wayne Fenton of the National Institute of Mental Health was killed by a 19 year old patient over Labor Day weekend. You can read the Washington Post's article of Sept 5, 2006.
Over the last 50 years, the number of people who connect mental illness with violence, though still a minority, has increased. Some studies suggest that the rates of domestic violence involving mentally ill adults against their family caregivers is higher than the rate of general domestic violence; or that while the vast majority of the mentally ill are no more violent than the general population, a small subset are more likely to commit more violent assaults. The question is pushed to a more public light since--like the rest of the nation since Ronald Regan's presidency--so many of Seattle's homeless are mentally ill, and so many self-defense students see them as a threat.
One of Strategic Living's core tenents is the need for accurate information to assess your real safety risk. Students in my classes almost always express concern about assault from strangers as their biggest safety fear. In fact, most assaults on women are committed by people know to them, and the risk is exacerbated with substance abuse. The same seems to be true for mentally ill assailants.
Rather than focusing on a person's label, it is more productive to look at their behavior. Some behavior keys include violating your physical space, verbal abuse, unwanted touch or staring, or trying to isolate you. Substance abuse and a fascination with guns and violence are also red flags. More women in Seattle will be assaulted in their own homes by their husbands than by homeless strangers. Homeless women are even more likely to be assaulted, also most often by significant others and acquaintances.
On a National Public Radio report about Dr. Fenton's murder, colleague Dr. Thomas Insel made it a point to say that violent acts committed by the mentally ill is highly unusual, and what is more likely is the mentally ill becoming assault victims. You can hear the interview with Dr. Insel on NPR's website.
If you would like citations for the studies mentioned, please contact Strategic Living.