Serial killers murder three or more victims on separate occasions and are divided into three categories: visionary, mission-oriented, and hedonistic. These murderers are known for carefully planning their crimes and having a distinct type of victim.
Much like The Replicator, a disgruntled FBI employee, many serial killers put detailed plans into motion. The Replicator used the BAU's previous cases against them by copycatting their crime scenes. The team took him down, but not before he murdered the unit's supervisor Erin Strauss.
"The Replicator" (Episode 24, Season 8)