How was Wayne Williams arrested?
Despite Williams matching Holdens psychological profile, the FBIs evidence at the time of his identification appears circumstantial. They know he was driving on a bridge early one morning and that a body was then discovered half a mile downstream later in the week. But there is no evidence to connect both events, and Holden and Bill meet continual opposition when pushing for search and wiretap warrants.
Due to what appears to be pressure from the mayors office, the district attorney finally grants a search warrant, and the FBI compiles forensic evidence on carpet fibers and dog hairs. Both the nylon fibers and animal hairs match those found on over a dozen victims. Convinced that the evidence will be substantial to convict Williams of at least two of the murders, the district attorney agrees to charge Williams, and he is arrested.
What happened after the arrest?
After the arrest, Holden meets with Camille Bell one final time. Bell is the mother of one of the first kidnapped children, who's also been leading her own search effort outside the local law enforcement and FBI investigation. She tells Holden that the FBI failed to find justice for the majority of the murdered children (given that Williams will only be tried for two of the crimes). Holden ensures her that he will be back to Atlanta and that investigators will work to connect more of the murders with Williams.
Holden and Bill then meet Gunn, their new FBI boss, on an airfield before leaving Atlanta. The private plane punctuates almost a year of passenger flights between Virginia and Georgia as well as an entire first season of economy class travel to prisons around the country. The travel upgrade, therefore, embodies the FBIs rising status among national law enforcement. According to Gunn, Atlanta changed everything and now the FBI will be first in. The teams profiling efforts and assistance with the Atlanta investigation thus set a precedent for federal intervention in similar state cases.
The consequence, however, is that the FBI will be relieved of the Atlanta case, and Holden and Bill are informed that the case has been downgraded to pending inactive, meaning FBI agents will stay on only in an assistant capacity. The district attorney will then be responsible for tying Williams with the other cases. Holden realizes that he inadvertently lied to Bell and that, as she feared, Williams will likely not be prosecuted for the remaining murders. In the final scene before the credits, Holden stands in hotel room, watching Atlantas police commissioner speak to reporters. He says that the case has been closed and that Williams will not be indicted for the other murders. Defeated, Holden hangs his head.
A text screen then appears to inform us of the outcome of the real-life Atlanta Child Murders case. Were told that as of 2019, none of the remaining 27 cases have been prosecuted.
What happened in that last last scene?
Season 3 officially ends where it opened: with Dennis Rader (the BTK killer) pleasuring himself by means of autoerotic asphyxiation. We see Rader in a hotel room with belongings of his victims arranged on a bed. Rader is dressed in women's clothing, and wearing a doll-like mask. He ties a rope around the doorknob and then leans forward violently.
The scene confirms several conclusions reached over the course of Mindhunters first two seasons: that killers will often relive their crimes sexually, that they collect trophies from the crime scenes, and that they can exhibit some kind of sexual deviance. Raders presence during the season also disconfirms several theories championed by Holden: that the majority of serial killers are products of broken homes, that they have trouble maintaining a job, and that they often live with parents. These factors had been the case for the majority of the men Holden and Bill interviewed. In one chilling scene, however, Ed Kemper reminds Holden that hes only ever interviewed serial killers who have been caught, and that, therefore, he may be mischaracterizing the most dangerous ones: those who avoid detection. Rader holds a steady job as an ADT installer. Hes married. He does not live with his parents. And as a result, he will not be apprehended for a number of years. Possible season 3 focus? We sure as hell hope so.
