(Portland, OR)  --  A homicide investigation is underway into the death of a 23-year-old man whose body was found last week in Hillsboro.  The Hillsboro Police Department confirmed yesterday afternoon that Alexis Vega-Cruz died from homicide.  His body was found last Wednesday night, but police aren't revealing where he was found or how he died.  Police say there are "many factors in the investigation" preventing them from giving more details.