You are to select a moral issue you find compelling?capital punishment, pacifism, abortion, what have you?and say what a deontologist like Kant would say about it.  Then you are to assess that argument.  Your paper should, then, be structured like this:
a)      Some people grant that capital punishment causes distress and pain to the capital criminal, but say that the criminal has earned his suffering.  This is a deontological argument in favor of c.p.
b)      Here?s what deontology is.  La la la.
c)      Here?s what I think about this deontological justification for capital punishment.  La la la.
You should be able to do this in about a single page.