What Jane Doe's Kit Can't Prove
The Jane Doe Files, Part 1 of 6
DNA was supposed to change everything about rape cases. In a sense it did: it freed innocent men, identified strangers, and made a few cold cases very hot. But in 1964, police cleared about 62% of reported rapes. By 2017 it was 32%, the lowest since the 1960s (AP via Chicago Sun-Times), and in 2025 it was 28% (FBI Crime Data Explorer). The most powerful identification tool in history arrived, and the share of rapes solved went down. Part of that is volume and mix: police now get about six times as many rape reports as in 1964, under a broader definition, and far more of them involve a man the victim knows.
The reason is simple once you see it. DNA answers one question: who was there? In most rapes, nobody is asking.
The question DNA can’t answer
About 78% of rape victims know the man who raped them (BJS). When the victim can name him, he rarely denies that sex occurred. He says she consented. A swab that confirms his DNA was present confirms what he’s already admitted.
The research on outcomes bears this out:
- A statewide Massachusetts study of 528 cases found that most arrests happened within a week, long before the lab reported results, which took a median of 43 days. Only about 2% of cases had an arrest that followed lab results. And among cases that went to prosecution, there were zero convictions where a DNA match was the only evidence (Cross, Alderden et al.).
- A federally funded Los Angeles study tested hundreds of backlogged kits and found testing produced “no new arrests,” one filing and two convictions, neither of which relied on the DNA. In matched recent cases, testing added modestly to arrests (2%) and convictions (11%) (Peterson et al., NIJ 2012).
- Earlier research found physical evidence doubled the odds of charges in stranger cases, and did nothing for them in acquaintance cases (Spohn & Holleran, 2004, as summarized in that study).
DNA isn’t irrelevant: when it matches, it strengthens a case, and a study of 137 cases from a nurse-examiner program found positive DNA evidence significantly increased the chance a case moved forward (Campbell et al., 2009). The National Institute of Justice’s own summary is the fairest one: forensic evidence “may have a substantial impact,” but “in relatively few cases” (NIJ).
So is the exam worth it?
That’s the uncomfortable question. A sexual assault forensic exam can take hours. It comes in the immediate aftermath of the worst thing that has ever happened to someone, and it involves being photographed, swabbed and examined by strangers. Survivors describe it as a second violation, and research has found that doctors and police “significantly underestimated the distress” their contact caused (Campbell, 2005; see also Campbell & Raja, 1999).
If the kit rarely decides her own case, why ask her to go through it?
There are three honest answers.
1. The exam is not all-or-nothing, and most people don’t know that. Under the Justice Department’s national protocol, a patient “may decline any portion of the examination” and can stop at any time. The speculum exam isn’t required in every case, and swabs can be taken without one. Underwear and clothing are commonly collected, and they can carry the attacker’s DNA without any internal exam at all (DOJ National Protocol, 2024). A 2009 study of 300 sexual assault cases in Buenos Aires province, Argentina, recovered the attacker’s DNA from underwear about 70% of the time, compared with about 60% for vaginal swabs (Bozzo et al.). Medical care (emergency contraception, HIV prevention, injury treatment) doesn’t depend on any of it.
2. She doesn’t have to decide about police that night. Since 2005, federal law has required states that receive Violence Against Women Act funding to offer the exam free “regardless of whether” the victim reports to police. These are often called Jane Doe kits: evidence collected and stored, sometimes anonymously, while she decides. Every state but one now has a formal option like this, with storage periods ranging from 90 days to 75 years. Hospital data suggest 20–25% of victims who seek care choose this option, and the limited research so far suggests only about 5% later convert their kit to a police report (Goodman-Williams et al., 2025). But for those who do change their minds, the evidence still exists.
3. Her kit may matter most for someone else. This is the answer the rest of this series builds toward. A kit that can’t prove her case can still put a DNA profile into the national database, where it may link to other assaults. The Los Angeles researchers concluded in 2012 that testing every backlogged kit wasn’t worth it, and that unsolved stranger cases should come first. Cleveland and Detroit tested everything anyway, and found hundreds of serial rapists, many of whom had attacked women they knew.
What about at-home kits?
If the hospital exam is the barrier, why not let victims collect their own evidence? A startup tried in 2019. State attorneys general in New York, Michigan and elsewhere moved against it, and New York’s called such kits “illegal, fraudulent, and deceptive,” mainly because evidence without a documented chain of custody may be useless in court (Jurist). Washington and Maryland have since restricted sales (Reason). For now, the evidence that counts has to be collected by a trained examiner.
The bottom line
The rape kit was sold to the public as the thing that would put rapists away. In most cases, it can’t, because most rapists are known to their victims, and the fight is over consent, not identity. That doesn’t make the kit worthless. It makes it a different tool than advertised: less a way to win her case than a way to find out whether he’s done this before.
Whether that’s a fair thing to ask of someone in the worst hours of her life is a question each woman gets to answer for herself. She deserves to know, when she answers it, that she can say no to parts of it, that she can wait on police, and what the kit can and can’t do.
Next in the series, Part 2: John Doe, Indicted. What happened when cities finally tested the kits sitting on their shelves.
Research and drafting assistance for this piece, including source verification, was provided by Claude (Anthropic). All claims are cited to primary or secondary sources linked inline throughout; the analysis and opinions are my own.