Almost two years after beating a stunned and unresponsive suspect in a public park, three Connecticut cops were finally placed on "desk duty" yesterday after footage of the attack had been made public.

The feds are now investigating the death of Kelly Thomas, a homeless, schizophrenic man who died earlier this month after being severely beaten by Fullerton, California police officers. If agents determine that Thomas' civil rights were violated, they'll send their info to the Department of Justice, who can file…