"It's usually homeless against homeless; it's very seldom homeless against people walking down the street," Pasquarello says.

While that fact doesn't lower the importance of the crime, it does make it harder to raise public awareness. What is a fact of life in one world is seldom heard of in another.

To many Cantabrigians the tribulations of the homeless are as far removed of those people in third-world countries.

But, police stress, recognizing a problem with homeless violence is not an attack on the Cambridge's homeless--just the opposite, in fact.

"One possible solution may be more services," one police report reads.

Substance abuse, prevalent in the homeless community, is one of the root causes of violence across the board--not just in the homeless population.

"The population we work with in CASPAR is under the influence of alcohol and drugs," says Gail E. Enman, CASPAR's executive director. "That fact can be a contributing factor, lowering inhibitions and leading to overreactions and violence." focus

Enman also says homeless women are particularly at risk, as witnessed by the Gardner killing.