Complex sentence: Sasser had been living in San Francisco for a couple of years in the 1990s, when Pedro Zamora moved into "The Real World" San Francisco loft, he and Sasser began dating.
Split into simpler sentences: Sasser had been living in San Francisco for a couple of years in the 1990s. When Pedro Zamora moved into "The Real World" San Francisco loft, he and Sasser began dating.