When reporter Matt Grant from WESH 2 News asked The Foundation for America's Homeless to show evidence of its work, the charity's CEO refused to do so. You can watch the interview here.
The fact that the charity isn't willing or able to provide evidence of its impact, along with inconsistencies on the charity's Form 990, should make donors run for the hills. Especially, since there are many highly-rated charities that help the homeless that are worth funding.
Remember, if a charity will not answer your questions, then find another that will.