Forensics: DNA

DNA is the molecule that contains the genetic code of organisms. With the exception of red blood cells, every cell in our body has DNA. We constantly shed DNA into the environment through skin cells, hair, saliva, blood, sweat, etc. DNA traces can be collected from our bodies or the environment and analyzed in specialized laboratories to reveal information about the individuals they came from.

Analysis of a DNA trace can provide basic information about the individual it came from, such as their genetic sex. Comparison of two DNA traces can determine whether they belong to the same individual, to individuals who are closely related genetically (e.g., parents and their children, cousins), or to unrelated individuals.

DNA in the environment degrades over time and under certain conditions, and a DNA trace must contain a sufficient amount of undegraded DNA to be successfully analyzed. As technology advances, this amount decreases.

In many countries, the State has DNA databases containing the genetic information of many individuals, often obtained during arrests or as part of criminal convictions. DNA is often treated in trials as the “gold standard”, indisputable proof that a person was in contact with the surface where their DNA was found.

See Dna You Say? Burn Everything to Burn Longer: A Guide to Leaving No Traces for a comprehensive overview of DNA forensics literature and the DNA topic.

Used in tactics: Incrimination

Mitigations

NameDescription
Careful action planning

Each step of an action plan can be rehearsed with an eye toward minimizing DNA traces at the site of the action. This may include, for example:

  • Securing your hair under a hat.
  • If you have to cut a fence, cutting any fence holes large enough to pass through without touching the fence.
  • Ensuring that surfaces at the site are not touched if they do not need to be, and that surfaces that need to be interacted with (such as a door handle) are touched by someone following DNA minimization protocols.
  • Ensuring that any destructive device left at the site (e.g. an incendary device with a delay) has worked as expected in tests conducted under similar conditions (temperature, etc.). The point of this is to make sure that the device will not be recovered intact by an adversary.
  • Ensuring that nothing is accidentally left behind such as a bag, tool, or anything that falls out of a pocket.
DNA minimization protocols

If you minimize the amount of DNA you leave on an object you manipulate, you minimize the risk that DNA forensics draws any valuable conclusion from an analysis of the object.

Gloves

You can wear gloves to prevent DNA from being left on objects you touch.

Used in repressive operations

NameDescription
Repression of Lafarge factory sabotage

In one of the initial raids, police insisted that those arrested wear surgical masks to protect against Covid: the masks were later taken for DNA collection[1]. One person who refused to wear a mask had their underwear confiscated while in police custody, presumably for DNA collection[2].

Repression of the first Jane's Revenge arson

In May 2022, DNA traces were collected from several items found by investigators at the crime scene, including a broken window, a glass jar, a lighter, and an intact Molotov cocktail[3]. In March 2023, police saw the comrade who was later arrested discard a brown paper bag containing a partially eaten burrito in a public trash can. DNA traces collected from the bag's contents matched those collected at the crime scene.

Case against Boris

The only evidence against Boris was that his DNA was found on a bottle cap at the foot of one of the burnt antennas from the April sabotage[4].

When DNA was collected from someone close to Boris during a house raid, only eight and a half hours elapsed between the collection of the DNA trace and the result of its comparison with other traces collected earlier.

2019-2020 case against Mónica and Francesco

Francesco's DNA was allegedly found on the parcel bomb sent to the former Minister of the Interior, which was defused and didn't explode[5].

Repression against Zündlumpen

The only clue against a suspected editor of the newspaper was that their DNA was found on a cigarette butt in the print shop raided in April 2022[6].

Panico

DNA traces were the only evidence against one of the accused comrades[7].

Prometeo

DNA traces were used to convict the comrade accused of burning an ATM[8].

Renata

After their arrest and imprisonment, the comrade accused of the explosive attack on the “Lega Nord” headquarters in Treviso refused to have their DNA taken[9]. Some time after the comrade's refusal, prison guards searched their cell and secretly replaced one comb with another, presumably to obtain the comrade's DNA from the hairs on the comb they took.

Scintilla

The charge against Peppe was based on a match between DNA traces found inside the parcel bomb and his DNA collected from a cigarette butt during the investigation[10].

Nea Filadelphia case

The charges against several comrades were based on a match between their DNA, taken by force while in custody, and DNA traces found on “mobile objects” near the robberies[11].

Mauvaises intentions

During police custody, DNA was collected from the comrades' clothing and from plastic cups[12]. In one case, only nine hours elapsed between the collection of a DNA trace in custody and the result of its comparison with another trace collected earlier.

The charges against a comrade were based on a match between his DNA and DNA collected at the scene of the attempted arson of the electrical cabinet. DNA traces were collected both from a latex glove found nearby and from a bottle inside the cabinet — which did not catch fire because of a failed delay.

The charges against other comrades were based on a match between their DNA and DNA collected from a cigarette used as a delay for an incendiary device — the delay failed and the device was found intact under the police tow truck.

Scripta Manent

DNA evidence was used to convict Alfredo Cospito[13].