Wellington resident Kesner Joaseus appeared to do brisk business, leasing single-family houses across Broward and Palm Beach counties—except for one hitch: The properties weren’t his to rent.

Joaseus collected more than $380,000 in rental income from vacant houses he entered and leased without the owner’s permission over about a two-year period beginning in November 2014, according to the U.S. Department of Justice.