"The majority of serial killers are not reclusive, social misfits who live alone. They are not monsters and may not appear strange. Many serial killers hide in plain sight within their communities. Serial murderers often have families and homes, are gainfully employed, and appear to be normal members of the community. Because many serial murderers can blend in so effortlessly, they are oftentimes overlooked by law enforcement and the public."
"Contrary to popular belief, serial killers span all racial groups. There are white, African-American, Hispanic, and Asian serial killers. The racial diversification of serial killers generally mirrors that of the overall U.S. population."
"All serial murders are not sexually-based. There are many other motivations for serial murders including anger, thrill, financial gain, and attention seeking."
"Most serial killers have very defined geographic areas of operation. They conduct their killings within comfort zones that are often defined by an anchor point (e.g. place of residence, employment, or residence of a relative). Serial murderers will, at times, spiral their activities outside of their comfort zone, when their confidence has grown through experience or to avoid detection. Very few serial murderers travel interstate to kill."
"It has been widely believed that once serial killers start killing, they cannot stop. There are, however, some serial killers who stop murdering altogether before being caught. In these instances, there are events or circumstances in offenders lives that inhibit them from pursuing more victims. These can include increased participation in family activities, sexual substitution, and other diversions."
"As a group, serial killers suffer from a variety of personality disorders, including psychopathy, anti-social personality, and others. Most, however, are not adjudicated as insane under the law."
"As serial killers continue to offend without being captured, they can become empowered, feeling they will never be identified. As the series continues, the killers may begin to take shortcuts when committing their crimes. This often causes the killers to take more chances, leading to identification by law enforcement. It is not that serial killers want to get caught; they feel that they cant get caught."
"Symposium attendees agreed that there is no single identifiable cause or factor that leads to the development of a serial killer. Rather, there are a multitude of factors that contribute to their development. The most significant factor is the serial killers personal decision in choosing to pursue their crimes. "
"Attendees at the Serial Murder Symposium agreed that there is no generic profile of a serial murderer. Serial killers differ in many ways, including their motivations for killing and their behavior at the crime scene. However, attendees did identify certain traits common to some serial murderers, including sensation seeking, a lack of remorse or guilt, impulsivity, the need for control, and predatory behavior. These traits and behaviors are consistent with the psychopathic personality disorder. Attendees felt it was very important for law enforcement and other professionals in the criminal justice system to understand psychopathy and its relationship to serial murder."
"Psychopaths are not sensitive to altruistic interview themes, such as sympathy for their victims or remorse/guilt over their crimes. They do possess certain personality traits that can be exploited, particularly their inherent narcissism, selfishness, and vanity. Specific themes in past successful interviews of psychopathic serial killers focused on praising their intelligence, cleverness, and skill in evading capture."
"An offender selects a victim, regardless of the category, based upon availability, vulnerability, and desirability. Availability is explained as the lifestyle of the victim or circumstances in which the victim is involved, that allow the offender access to the victim. Vulnerability is defined as the degree to which the victim is susceptible to attack by the offender. Desirability is described as the appeal of the victim to the offender. Desirability involves numerous factors based upon the motivation of the offender and may include factors dealing with the race, gender, ethnic background, age of the victim, or other specific preferences the offender determines."
http://www.fbi.gov/stats-services/publications/serial-murder
It's so hard to say though. I sure as hell think he looks sketchy. But he might have talked a good game and been like "I know your mom, dad, etc and I'll help you". 
