I have also seen an older guy sleeping on the lawn in Peninsula Park (Gantry Park).  It is tough to tell he is homeless because he looks pretty clean and travels light but I have seen him sleeping on the lawn when I finish jogging and I walk around the lawn to cool down at 6:30 am.  I guess once it starts to get colder he will have to move on.  However, our local precinct should get involved and make sure this people are pointed to the city services and just left alone.