Complex sentence: As it happened, Lavern Hale had been a neighbor of Allen's, living directly behind his house, and he remains a suspect in her murder, based upon the killer's "modus operandi".
Split into simpler sentences: As it happened, Lavern Hale had been a neighbor of Allen's, living directly behind Allen's house. Allen remains a suspect in Hale's murder, based upon the killer's "modus operandi".