Complex sentence: They filed a police report where the FBI became involved, however, the case stalled until President Lyndon Johnson, who had recently passed the Civil Rights Act, allowed the FBI to look into it as a civil-rights violation.
Split into simpler sentences: They filed a police report where the FBI became involved. However, the case stalled until President Lyndon Johnson, who had recently passed the Civil Rights Act, allowed the FBI to look into it as a civil-rights violation.