Digital DNA Heating Up Cold Cases

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In the United States, approximately 250,000 unsolved murders occur each year, according to the Uniform Crime Report. This is a clearance rate of about 50%, a drastic decrease from the 90% clearance rate for homicides in the 1960s. While this decrease is in some way due to criminal justice reform and more accurate reporting, it is undeniable that this decrease is also affected by the increasing murder rate we saw starting in 2020.  

Unsolved criminal investigations (homicides or abductions) that are no longer actively pursued because of lack of evidence are defined as cold cases. In other words, when an investigation goes idle, it is often assumed that the case is hopeless, impossible, and will never result in justice. Historically, this suggests that these violent offenders who have not been caught will continue committing crimes. Many of these violent crimes are still unsolved despite the full potential of deoxyribonucleic acid (DNA) evidence and national DNA databases. 

Beyond DNA evidence is the power of open-source intelligence (OSINT). With advancements in technology and social media engrained in today’s culture, it is rare for individuals not to have digital footprints – potential evidence for law enforcement. This raises the question: when DNA or other traditional forms of investigation fail, could a few quick online clicks help investigators keep a case from going cold? 

In this edition of Overwatch, analysts interviewed two individuals at the Criminal Investigations Division at the Hillsborough County Sheriff’s Office (HCSO) in Tampa, Florida to understand how digital footprints can aid law enforcement. Analysts also selected a cold case provided by the Hillsborough County’s Sheriff’s Office, an unsolved homicide, showing how OSINT could be applied to support an investigation. 

Interview with Hillsborough County Sheriff’s Office Criminal Investigations Division 

Overwatch: How often does a homicide or violent crime have a digital footprint? Has law enforcement increasingly turned to social media to find suspects of crimes?  

HCSO: We try to use social media searches in almost every homicide, except open and shut ones that are closed in 24-48 hours. However, we lack advanced tools, tips, and tricks of the trade to narrow down the information found online. We rely on free knowledge but using social media platforms in investigations today is extremely common, especially in shootings and gang violence, specifically in neighborhoods with turf wars. So, looking on social media has been helpful because people aren’t typically forthcoming.  

Overwatch: What are some of the challenges faced when it comes to pursuing a digital footprint of a potential suspect? For example, are search warrants needed? Are laws applicable in the digital space? 

HCSO: Privatized accounts are a huge issue. If you want information from private accounts, detectives need enough information to send a warrant to the social media company. The Sheriff’s Office here often gets Facebook and Instagram search warrants; however, the speed at which we receive the information back from the company is decided on a case-by-case basis. Sometimes it can be super slow, especially if it’s not a pressing matter.  

Overwatch: Can you tell me about a time when the Hillsborough County Sheriff’s Office was able to solve a cold case or homicide because of a victim or perpetrator’s strong digital footprint?  

HCSO: There was a case that we came to a dead end. However, our investigation found a couple that often made TikTok videos. We monitored their profiles, and while they didn’t make videos about the crime or anything like that, the lead came because they made a video in a vehicle that placed them in the suspect’s vehicle. So, their digital presence provided a clear lead which, coupled with other evidence, allowed the case to be solved. 

Tracks Left Behind 

In 2020, Hillsborough County had 37 homicides reported, with 27 solved or cleared. This was the highest rate of homicides in the last 10 years, according to the Federal Bureau of Investigation’s Crime Data Explorer 

In today’s world, the internet is entrenched in everyone’s daily life, increasing the opportunity to use the massive amounts of publicly available information to reopen cold cases. We have all heard of cases where a suspect’s or victim’s digital footprint pointed law enforcement in the right direction during an investigation, despite a lack of DNA evidence. Examples include a university student who was discovered dead after her last cell phone signals were found in a remote area with another person or a mass murderer who left cryptic messages on digital forums days before carrying out an attack. Like DNA left at a crime scene, the same can be said for online activity varying from malicious websites, social media posts, interactions, and connections – all of which leave digital data in their wake. 

Murder Case Gone Cold 

Overwatch analysts visited the Unsolved Homicide website run by the Hillsborough County Sheriff’s Office to find an unsolved homicide and apply advanced search OSINT techniques. Analysts selected the cold case of Ariel Pagan-Colon. They started discovery by focusing on online chatter, looking at the date of the murder, the scene of the crime, and the victim’s social media presence.  









The event occurred on July 13, 2019, when Ariel Pagan-Colon was “shot to death outside of a house party…” according to the Hillsborough County Sheriff’s Office Unsolved Homicides website. Analysts implemented advanced search queries to narrow down social posts related to the murder of Mr. Pagan-Colon.  

On July 13, 2019, Twitter user @jason_rohena posted about the victim’s death, insinuating that he was shot by one of his friends. The tweet was posted at 9:16 pm. A search on the Hillsborough County Sheriff’s Office “Calls for Service” website shows the location and date of Mr. Pagan-Colon’s incident. The service call was at 9:09 pm. This means that the Twitter user posted moments after the 911 call. Due to the speed of the post, it is possible that the user was at the crime scene and has more information about the suspects.  

A further look into the victim’s lifestyle and close associates revealed that his girlfriend was possibly at the location where the crime occurred. Moments before the deadly event, it appears that he was waiting outside the home where a party was occurring while his girlfriend was making her way outside to meet him, according to a Facebook post from the victim’s mother.  

The victims girlfriend was found on Facebook, and analysts were able to examine the information posted there about the victims passing. She wrote on Facebook, Not seeing your message has me broken, on December 31, 2019. It was not revealed what the message she received from the victim was. However, its possible that she received information minutes before his death that could add to the timeline of events or even insinuations about who the murderer could be. 

Analysts also found a social media post that denigrated the victim and alluded to a potential foe. This is not proof that the person who commented is accountable for Mr. Pagan-Colons death. Yet, the post may lead to a list of people who did not get along with the victim, despite the gap in time between it and the date the victim was killed. 

Our Assessment 

On television shows or movies, DNA, like fingerprints on a weapon or saliva on a discarded cigarette, are typically the evidence that solves cases. In reality, DNA is not always available in violent crimes, particularly homicides. However, many people do leave digital evidence. In the case of Mr. Pagan-Colon, his robust digital footprint can aid law enforcement in developing the case further based on discreet digital clues. 

In the case of Mr. Pagan-Colon, the victim was in his early 20s and often attended parties and clubs using social media to keep in touch with his old high school friends and family. A trail of photos and memorable moments from these events were often posted on social media by the victim. A timeline and biography of the person of interest can be found by following his digital footprint. It is possible that the details surrounding the house party where he was murdered can be found online. While we are unsure of the specifics of the crime, analysts can confidently state that the victim’s digital footprint supplied a clear picture of his lifestyle, social network, and activities in the days preceding his death.  

As the homicide rate rises, analysts assess that more crimes will become cold cases. More consideration of digital footprints in cold case homicide investigations is necessary, given this possible rise. Due to the budget constraints facing many police departments, the investment of open-source intelligence (OSINT) tools creates a financial barrier for many police departments. This makes it even more crucial that cost-effective resources and manual methods be spread to departments nationwide to surmount this artificial barrier. While traditional investigation methods such as DNA analysis will always be necessary, proper OSINT training and techniques can be a cost-effective resource to help deal with crimes that have gone cold.