Complex sentence: In May, 2008, someone broke into the Zoo when it was closed and broke into the Spider Monkey enclosure and killed Jocko (the male monkey) and kidnapped Mia (the female monkey).
Split into simpler sentences: In May, 2008, someone broke into the Zoo when it was closed. The intruders entered the Spider Monkey enclosure, killed Jocko (the male monkey), and kidnapped Mia (the female monkey).