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Factors Contributing to the Decline in Serial Murders: Advancements in Technology,
Science, and Law Enforcement
Madison H. Sparks
Stevenson University
FSCI500: Fundamentals of Forensic Science
Prof. Stephanie Leaf
October 11, 2024
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Factors Contributing to the Decline in Serial Murders: Advancements in Technology,
Science, and Law Enforcement
The recent decline in serial homicides can be contributed to lower numbers of serial
killers, an increased understanding of their typical characteristics, and advanced methods of
identification. There is a misconception that the number of murders has not declined, but I will
demonstrate why that is untrue. The definition of the term “serial killer” is not completely agreed
upon, but the most consistently and widely used baseline definition is the FBI’s: they have at
least three victims with premeditation and “cooling off” periods between them (Miller, 2014a).
Intentionality is a defining characteristic of serial killers (Yaksic et al., 2021). Other common
character traits include the prevalence of alcohol and drug use and abuse, working in unskilled
jobs, and previous exposure to criminal behavior (Yaksic et al., 2021). The increase in popularity
of true crime may have affected how the public perceives this issue, mixing up unsolved murders
with serial killers who have not yet been caught (Yaksic et al., 2019). This paper and most
references will focus on the United States, because it is the country with the highest prevalence
of serial homicide offenders (SHOs).
Multiple factors are contributing to the lower numbers of serial killers. There are more
people behind bars than in previous time periods, likely due to improved response from law
enforcement. Catching serial homicide offenders or potential serial offenders means there are
fewer serial killers roaming free (Yaksic et al., 2021). Criminal behavior including burglary and
rape may possibly predict future murders, so convicting these offenders may prevent those future
murders from occurring. Stricter parole policies and longer prison sentences are also contributing
to fewer serial killers (Aamodt et al., 2023).
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The actual numbers of active serial killers are disputed. The number of active killers
ranges from a conservative 30 to an exaggerated 500 (Yaksic et al., 2019). Spree killers, aspiring
serial killers, and probable killers are often lumped in with serial killers, making people doubt
that there is an actual decline in the number of true serial killers (Yaksic et al., 2019). The
popularity of true crime has skyrocketed. Multiple popular murder documentary series and
increased media coverage cause the perception of more violence and skews the perceived
numbers of serial killers (Yaksic et al., 2019). The pop culture presence of serial killers has led to
may persistent myths, including the common beliefs that most killers want to be caught, they
cannot stop killing, and murderers have a prototype (Williams, 2016).
Database statistics and serial homicide research also provide evidence of the decline in
the number of serial killers. While the number of known killers and the number of victims
peaked in the 1980s (1987), these numbers have declined since (Aamodt et al., 2023). Other
influences on the change in number include better technology, shifts in behavior, proactive law
enforcement action, and the increased vigilance of society (Yaksic et al., 2019). Leisure studies
coinciding with forensic studies have contributed to a better understanding of serial homicide
(Williams, 2016). For example, behavioral genetic research suggests that violent behavior may
have to do with a person’s genetic inability to properly transport and detect neurotransmitters
like dopamine and serotonin (Williams, 2016).
Other factors that may be precursors to serial killing have also been studied, and these
include abuse, emotional instability, antisocial personality, and childhood mistreatment (Yaksic
et al., 2021). These studies result in a better understanding of the characteristics exhibited by
serial murderers. Forensic psychiatric research has made people more aware of warning signs
these murderers may show. The classic trio of signs that appear in children who may grow up
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with violent tendencies include late bedwetting, fire setting, and the killing and/or torturing of
small animals (Miller, 2014b).
Yaksic and colleagues (2019) described general trends of characteristics and tendencies
exhibited by known murderers. Because of this, investigators know to look for a signature
method or similarities between scenes (Miller, 2014a). Yaksic et al. (2019) showed that their
study cohort conformed to an archetype defined by preplanning murders, sexual or deviant
motivations, more intimate methods of killing, and attempting to throw off investigators.
Improved law enforcement technology and strategies, including the National Unidentified
and Missing Persons System (NamUs) and the Violent Criminal Apprehension Program (ViCAP)
have aimed to shorten the active killing phase as these criminals are detained before they reach
serial killer status. The NamUs program combines people, information, forensic science, and
technology and helps solve missing and unidentified person cases across the country (National
Missing and Unidentified Persons System, 2021). ViCAP is an FBI program that collects and
analyzes information on violent crimes, including homicides, sexual assaults, kidnappings, and
missing person cases (NamUs, 2021). ViCAP allows law enforcement agencies across the
country to share information (Hood et al., 2022). Law enforcement’s awareness of potential
victims may contribute to a shift in offending behavior, as more aspiring/probable serial killers
are caught before they can reach the status of serial killer. By failing to become serial killers,
they have impacted the rate of serial murder (Yaksic et al., 2019).
Another change that has likely decreased the number of serial killers is that the public as
a whole is more cautious. Situations that make people easy targets, such as hitchhiking and
children playing outdoors unsupervised, have decreased (Aamodt et al., 2023; Yaksic et al.,
2019). The vetting of people getting jobs like truck driving and in medical roles has become
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stricter (Yaksic et al., 2019). Increased awareness of and treatment for childhood abuse, which
often leads to several emotional issues, can help prevent violent fantasies from being carried out
by these victims. Better access to mental health help might further decrease these violent crimes.
Advancements in forensic science and technology have led to better identification
methods. The proliferation of cell phones, facial recognition software, and higher quality security
systems all impact the success of serial murderers (Yaksic et al., 2019). The internet provides an
outlet for potential offenders which may prevent them from acting out their fantasies on actual
people. Potential killers may participate in internet forums with likeminded people and have
access to pornography and photos of anything they want to see (Yaksic et al., 2019). For some
potential killers, this sort of online activity may be enough to suppress their urges.
Development of more advanced DNA technology allows for several sources of material
(such as different body fluids, fibers, or skin cells) that can yield results (Butler, 2023). There are
now rapid DNA systems that are available to law enforcement including The Accelerated
Nuclear DNA Equipment (ANDE), and the RapidHIT ID. These systems allow for quicker
processing of samples that contain DNA and can be used in a variety of situations. Their value in
homicide investigation lies in the ability to process evidence at crime scenes and compare DNA
profiles to forensic databases while the suspect is in custody (Butler, 2023). Limitations,
however, include the fact that their use should be limited to samples such as buccal swabs that
are easy to collect numerous times (Butler, 2023).
Computerized databases such as Combined DNA Information System (CODIS) and
Integrated Automated Fingerprint Identification System (IAFIS) are extremely helpful in
allowing law enforcement to compare DNA or fingerprints to known offenders and across
jurisdictions. When CODIS was established, it was seen as possibly the most significant
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advancement of the 20th century because it greatly improved the speed and accuracy of matches,
or “hits” (Hood et al., 2022). Another interesting advancement that may help identify potential
SHOs is the presence of genetic testing services like 23andMe. Data from these services is now
able to be used in forensic genetic genealogy, allowing access to DNA that would not exist in
CODIS or other databases (Hood et al., 2022). These technologies did not exist during the peak
of serial killers (sometimes called the “golden age” according to Yaksic et al., 2019) so it was
easier for them to get away with their crimes. The simple knowledge that such technology exists
is potentially a deterrent for would-be serial killers, contributing to decreased prevalence.
As highlighted by Kabir et al. (2013), there are a variety of techniques emerging to
analyze forensic evidence more easily while overcoming the obstacle of the necessity of large
quantities of samples. For example, the ability of forensic chemists to test a sample without
destroying it so that it can be maintained as evidence allows for more detailed and specific
results. Several forensic applications useful in placing suspects at a crime were mentioned in the
article. These include laser-induced breakdown spectroscopy (LIBS) to analyze fibers and glass,
micro-Raman methods for identifying components in inks, and more efficient sample collection
of gunshot residue (Kabir et al., 2013) The analysis, identification, and comparison of various
evidence samples has become easier as machines have become more sensitive and require less
sample material (Kabir et al., 2013). This along with improved sample collection methods allow
tiny details of trace evidence to be the key to conviction.
There have been numerous studies on serial killers in the 21st century, however, there still
is not a full understanding of how these people develop these tendencies. The decline in serial
murders, though evident through the limited existing studies, is still disputed among researchers
and the general public. However, experts can agree on the reasons for the potential decline in the
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number of serial homicides, including fewer serial killers, a better understanding of their typical
character traits, and advanced identification technologies and methods.
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References
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