DNA Evidence in Federal Cases: What the Crime Shows Don't Tell You

Welcome to the Spodek Law Group resource library. We believe everyone deserves access to clear, honest information about the federal criminal justice system - especially when your freedom hangs in the balance. Our team, led by Todd Spodek, has spent years fighting federal cases where DNA evidence seemed insurmountable. What we've learned might change everything you think you know about DNA.

You've seen the crime shows. DNA match. Case closed. The detective nods confidently, the prosecutor smirks, and the defendant's fate is sealed. But those shows skip the part where a human analyst decides what the DNA "means" - and seventeen experts looking at the same evidence produced different conclusions.

That's not dramatic license. That's a peer-reviewed scientific study. And it might be the most important thing you read today.

When 17 Experts Disagree on the Same DNA

Heres the thing about DNA evidence that nobody wants to discuss in open court. The raw data coming off the sequencing machine isnt a yes-or-no answer. Its a complex pattern of peaks and valleys that requires human interpretation. And that interpretation is were everything can go wrong.

In a landmark study published in the scientific literature, researchers took DNA mixture evidence from an actual criminal case - evidence that had already been used to convict someone - and sent it to seventeen diffrent forensic DNA experts across North America. These werent random people off the street. These were qualified, certified, working forensic analysts.

The result? The majority of those experts disagreed with the testimony that had been presented at trial. Only one of the seventeen agreed with the original analyst's conclusion. Same DNA. Same data. Completly diffrent interpretations.

Think about what that means. The analyst who testafied against you might have been the outlier. Sixteen other equally qualified experts might have looked at that evidence and said something entierly diffrent. But the jury only heard one opinion. The prosecutions opinion.

This isnt about bad apples or incompetent labs. This is about the fundemental nature of DNA mixture interpretation. When you have DNA from multiple people mixed together - which is extremly common in real-world crime scenes - the process of figuring out who contributed what becomes subjective. The analyst makes judgement calls about which peaks to include, which to ignore, how many contributors there were, and weather the evidence is strong enough to call a match.

Read that again: subjective judgement calls determine if you go to prison.

And heres were it gets worse. Research has shown that forensic analysts can be influenced by contextual information about the case. If they know details about the suspects criminal history, if theyve seen the defendent's reference DNA profile before analyzing the crime scene sample, if theyve been told what the prosecution expects to find - all of these factors can unconciously bias there interpretation.

The same study that sent evidence to seventeen experts also found that analysts who knew about the criminal case context were more likely to include the defendant then analysts who looked at the DNA evidence "blind." This isnt conscious corruption. Its human psychology. And its built into how crime labs opperate.

The FBI Lab Scandal: 90% Error Rate Nobody Talks About

If you beleive the FBI crime lab is the gold standard of forensic science, you probly havent heard about what happened with there hair analysis testimony. In 2015, the FBI acknowledged that its microscopic hair comparison analysts had given erronous testimony in at least 90 percent of the cases that were reviewed.

90%. Thats not a typo.

Legal analysts called the announcement a "watershed in one of the country's largest forensic scandals." The Washington Post reported that these errors highlighted the failure of the nations courts for decades to keep bogus scientific information from juries. According to data from the Innocence Project, seventy-four of the 329 wrongful convictions overturned by DNA evidence involved faulty hair evidence from analysts who made these same types of errors.

Twenty-six of twenty-eight FBI examiners provided either testimony with erronous statements or submitted laboratory reports with erronous statements. This wasnt a few isolated incidents. This was systemic, spanning decades, affecting thousands of convictions.

And DNA analysis? The FBI's DNA unit had its own scandals. An analyst named Jacqueline Blake worked in the FBI DNA unit from 1988 until her resignation in 2002. An internal investigation revealed that she had failed to process negative controls - a basic quality assurance step that would of caught contamination. Her failure to follow protocal rendered all of her DNA analyses scientificaly invalid.

Twenty-nine DNA profiles had to be removed from NDIS, the national DNA database. Retesting in many of her cases took upwards of two years to complete. And the most disturbing part? Her collegues thought it was "inconcievable" that a fellow employee would skip such a basic step. Nobody was looking becuase nobody imagined it could happen.

Heres the kicker. Labs get there funding from the goverment. The same goverment thats prosecuting you. There is no incentive structure for crime labs to produce defense-favorable results. Every conviction-friendly report strengthens there funding case. Every doubt-raising analysis creates problems.

This dosent mean every lab tech is corrupt. It means the system itself creates pressures that push toward prosecution-favorable interpretations. And when human judgement is involved - as it always is with complex DNA mixtures - those pressures matter.

Secondary Transfer: Convicted Without Being There

Picture this scenario. Your at a coffee shop. You shake hands with a stranger. A perfectly normal, forgettable interaction that you wont even remember tommorow. That stranger leaves, commits a crime hours later, and touches a murder weapon.

Your DNA is now on that weapon.

This is called secondary DNA transfer, and its not hypothetical. Research at the University of Indianapolis asked pairs of volunteers to shake hands for two minutes, then had them handle knives. The results were terrifiying. In 85 percent of the cases, DNA from the person who did NOT touch the knife transfered in sufficent quantity to produce a profile.

And in one-fifth of those samples - 20 percent - the person who never touched the knife was identified as the main or only contributer of DNA to the potential weapon.

Your DNA can convict you for a crime you never commited, at a location you never visited.

The case of Lukis Anderson demonstrates this isnt theoretical. In 2012, Anderson - a homeless man in California - was charged with the murder of a Silicon Valley millionaire. DNA evidence on the victim's fingernails matched Anderson. It looked like an open-and-shut case.

Except Anderson was in a hospital bed at the time of the murder. He had been hospitalized for severe intoxication and was under constant medical supervision. He had an alibi verified by hospital records, security cameras, and multiple witnesses.

How did his DNA end up at a crime scene he never visited? Paramedics. The same paramedics who had treated Anderson earlier that evening also responded to the murder scene hours later. His DNA hitched a ride on there gloves or equipment and was deposited on the victim.

The case was eventualy dismissed and has been presented at forensic science conferences as a definitive example of how DNA can implicate the completly innocent. But think about how close Anderson came to a murder conviction. If he hadnt had rock-solid hospital records, if the investigation had been less thorough, if his public defender hadnt thought to question the DNA - he could of spent the rest of his life in prison for touching absolutly nothing.

The scary truth is that "touch DNA" technology has become so sensitive it can detect cells from skin you shed while walking through a room. And theres currently no reliable way to determine weather DNA arrived through primary transfer (you touched it), secondary transfer (someone who touched you touched it), or even tertiary transfer (even more removed).

Think about the implications for a moment. You ride the subway. You hold a handrail that hundreds of other people have touched. Your picking up there DNA and depositing yours. Someone else grabs that same rail after you. They now carry your cells. Hours later, they handle an object that becomes evidence in a crime you know nothing about.

The research on this topic has not kept pace with the technology. Labs can now extract profiles from incredibly small samples - as few as seven or eight skin cells. But our understanding of how easily those cells transfer, and how to determine the method of transfer, remains extremly limited. Your literally being judged by science that hasnt caught up to its own capabilities.

Why Prosecutors Withdrew Evidence Rather Than Reveal the Code

When DNA mixtures are to complex for human analysts to interpret, crime labs increasingly turn to probabalistic genotyping software. Programs like TrueAllele and STRmix use algorithms to calculate the likelyhood that a particular person contributed DNA to a sample.

These programs have been used in hundreds of criminal cases. Defendants have been convicted based on there results. And for years, defense attorneys couldnt examine how the software actualy worked becuase the source code was protected as a trade secret.

In the case of NY v. Hillary in 2016, a defendant was charged with murder based partly on STRmix analysis. His defense team filed a motion to exclude the software evidence, arguing it wasnt generally accepted in the scientific comunity. The judge agreed and precluded the prosecution from presenting STRmix results.

But heres what makes this truly disturbing. When researchers have compared these programs, they produce radically diffrent results from the same DNA evidence. In one federal case, STRmix said the defendant should be EXCLUDED as a contributor - meaning the DNA evidence supported his inocence. TrueAllele, analyzing the exact same data, produced a likelyhood ratio of 16.7 million in favor of inclusion.

Same DNA. Same mixture. One program says innocent, the other says guilty. And neither company will show you exactly how there algorithm made that determination.

Computer science experts estimate that software of this complexity inevitabley contains bugs. TrueAllele has approximatly 170,000 lines of code. At industry-standard error rates of six bugs per thousand lines, thats potentialy over a thousand software bugs determining weather you go to prison.

When judges have ordered prosecutors to reveal the source code for independant review, some prosecutors have chosen to withdraw there DNA evidence intirely rather than comply. If the software is reliable, if it has nothing to hide, why would that be preferable to transparency?

The Presidents Council of Advisors on Science and Technology has noted that many validation studies for these programs were conducted by people affilated with the companies that make them. These are not independant evaluations. The people who stand to profit from the softwares continued use are the same people testifying to its reliability.

And yet prosecutors present these results to juries as if they were mathematical certainties. The likelyhood ratio is displayed with impressive precision - 16.7 million, not "somewhere between 10 million and 20 million." But that false precision obscures enormous uncertainty about weather the underlying algorithm is even producing correct results.

The Exclusion vs Inclusion Paradox

Defendants facing DNA evidence often hear a confusing claim. If DNA evidence is so problematic, why has the Innocence Project used DNA to exonerate over 375 wrongfully convicted people? Does not the success of DNA exonerations prove the technology works?

The answer reveals a crucial distinction that prosecutors rarely explain.

DNA evidence is excellent at exclusion. Proving someone was NOT the source of DNA is relativly straightforward. If the DNA profile from a crime scene does not match your DNA profile, you can be definitavely excluded. The biology is binary. Either the alleles match or they dont.

But proving someone WAS the source of DNA - inclusion - is a completly diffrent matter. Inclusion requires interpretation. And interpretation is were subjectivity enters. Interpretation is were mixture analysis creates ambiguity. Interpretation is were analyst bias can influence conclusions.

Those 375 exonerations? The people freed by DNA testing had typicaly been convicted BEFORE modern DNA analysis was available, or on DNA mixture interpretations that were later shown to be flawed. The same technology that freed them could not have convicted them in the first place if used properly. But it was used improperly. Prosecutors presented DNA evidence as certain when it was actualy ambiguous.

Many of the wrongful convictions overturned by DNA evidence actualy involved DNA evidence that was misinterpreted at trial. The science didnt change. The willingness to acknowledge uncertainty did.

Heres another way to think about it. When you take a DNA test for ancestry or paternity, your submitting a clean, single-source sample under controlled conditions. The results are reliable becuase the conditions are ideal. Crime scene DNA is nothing like that. Its degraded, contaminated, mixed with multiple contributors, collected under unpredictable circumstances. The gap between laboratory-ideal DNA analysis and real-world crime scene analysis is enormous.

Lukis Anderson: Charged With Murder While Hospitalized

December 2012. Raveesh Kumra, a wealthy Silicon Valley investor, is murdered in his home during a robbery. Investigators find DNA under his fingernails. That DNA matches Lukis Anderson, a homeless man with a criminal record.

The case seems straightforward. DNA at a murder scene matching a known criminal. Prosecutors move forward with charges.

But Andersons public defender starts asking questions. Were was Anderson the night of the murder? Hospital records show he had been admitted for severe alcohol intoxication. He was so incapacitated he required constant medical attention. Security footage confirms he never left the hospital.

How could his DNA be at a crime scene when he was physicaly incapable of being there?

Investigators eventualy pieced together the answer. Paramedics who had responded to Andersons medical emergency earlier that evening were the same paramedics who later responded to the murder scene. Andersons DNA - probably from his skin cells or bodily fluids - transferred to there gloves or equipment and was deposited on the victim hours later.

Charges were dismissed. But the case has become a teaching example at forensic science conferences about the dangers of relying on DNA presence to establish guilt.

Andersons experience is not unique. Its just unusualy well documented becuase of the hospital alibi. How many people have been convicted on secondary transfer DNA who didnt have security cameras proving there whereabouts?

And consider the Kerry Robinson case. Convicted of rape in Georgia based on DNA evidence. When researchers later submitted that same DNA mixture to seventeen expert analysts, only ONE agreed with the trial testimony that had convicted him. Sixteen others would of reached diffrent conclusions. Robinson was eventualy exonerated, but not before years of wrongful imprisonment.

These arent cherry-picked examples. The Equal Justice Initiative reports that innocent Black people are about seven times more likely to be wrongfully convicted of murder then innocent white people. Many of these wrongful convictions involve forensic evidence that was presented as certain but was actualy far more ambiguous then the jury was told. The system produces false certainty, and the most vulnerable people pay the price.

The Chain of Custody Attack Your Attorney Should Be Running

If your facing federal charges involving DNA evidence, your defense attorney should be conducting a comprehencive challenge on multiple fronts. The science isnt unbeatable. The question is weather your attorney knows how to beat it.

Start with chain of custody. DNA evidence is extremly sensitive to contamination. Every person who handles the evidence, every lab the evidence passes through, every storage facility - these all represent potentiel points where contamination, degradation, or mishandeling could occur. Your attorney should demand complete documentation of everywhere that evidence has been from crime scene to courtroom.

Next, examine the lab itself. What are its accreditation status, error rates, and history of problems? Has this specific lab ever had evidence excluded from court? Have any of its analysts been disciplined or had there testimony challenged? Crime labs vary dramaticaly in quality, and federal prosecutors dont always use the best availible facilities.

Challenge the interpretation methodology. If the DNA evidence involves a mixture, how did the analyst decide how many contributors there were? What peaks did they include or exclude? Did they examine the evidence blind, or did they know details about the suspect before analyzing? The Dror-Hampikian study shows that the same evidence can support completly diffrent conclusions depending on who interprets it.

If probabalistic genotyping software was used, demand access to validation studies, error rates, and idealy the source code itself. Some courts have begun ordering disclosure. If prosecutors refuse, argue that constitutionally guaranteed confrontation rights require your attorney to examine and challenge the specific methodology that produced the evidence against you.

Every break in the chain is a crack in there case. Every questionable interpretation is reasonable doubt.

At Spodek Law Group, we work with independant DNA experts who can review the government's analysis and identify weaknesses. We've seen cases were the prosecutions DNA evidence fell apart under scrutiny - not becuase the DNA was planted, but becuase the interpretation was flawed, the methodology was questionable, or the chain of custody had gaps.

DNA evidence can be challenged. DNA evidence has been challenged successfully. But it requires attorneys who understand the science well enough to identify were the government's case is weak.

If your facing charges were DNA evidence is central to the prosecution, you need counsel who understands that DNA is data requiring interpretation - and that interpretation can be wrong. Call us at 212-300-5196. The consultation is confidential, and the conversation might change how you see your case.

Todd Spodek and the team at Spodek Law Group have fought federal cases across the country. We know that what looks like insurmountable scientific evidence often has cracks that only experience reveals. Dont let the crime show version of DNA convict you. Let us show you what the evidence actualy means.