Police are still seeking one or possibly two additional suspects in the homicides.
Officials have said 19-year-old Aleah Hamlin, 23-year-old Chanel Armour and 21-year-old Alphe Rene were shot execution-style inside an apartment on North 13th Street.
Arrest papers in the case have been sealed, but Morganelli says he believes the killings were gang-related.