Hacker News Reader

Comment by MichaelGG | Hacker News Reader

Does DNA testing work like that? If so, you'd just build more iterations into the test itself. If they refer to taking another sample, again, for such a critical test, why not take multiple samples? The coin analogy seems misleading as you can flip many times for free, and each flip is (usually) completely independent.

It'd seem a retest would only matter if there's a new test or the previous test was suspected to be improperly done. In any case, you'd need a reason to believe a different outcome is possible.

In this case, a quick search finds[1]. It says evidence and sample procedures were not properly followed, and there wasn't even evidence of blood on the knife.

I'm all for being corrected on statistics, but this doesn't seem like a case of bad math, does it?

1: http://www.westseattleherald.com/2011/06/29/news/update-dna-...

View on HN

More to the point, even if her blood was on the knife would that necessarily be conclusive evidence? I know that I've left a bit of blood on various cooking knives of people I've lived with.

No offense (maybe a giggle) but that seems highly unusual

I cut myself cooking sometimes. Nothing to be proud of, but hardly unusual I'd think.

Anyone that isn't a professional chef is probably going to leave a little blood on a knife by cutting themselves with it.

There's a difference between a knife drenched in blood and a tiny bit of blood from a cut, certainly, but as far as forensics goes that may not matter - they may want to find any evidence of blood, like some blood caught in the space between the handle and the blade, on the assumption that a killer may have tried to clean blood off a weapon.

> on the assumption that a killer may have tried to clean blood off a weapon

Surely cleaning blood off the knife makes just as much sense if it was a cooking accident as if you've killed someone with it?

> Anyone that isn't a professional chef is probably going to leave a little blood on a knife by cutting themselves with it.

That's a strong claim.

I'm not a professional chef but I like to use a chef's knife, and I cut rather fast. Yet I don't remember ever cutting myself to the point of bleeding. I only remember scraping off nails and skin.

> like some blood caught in the space between the handle and the blade

I reckon that if it gets stuck between the handle and the blade then we're talking about more than a little blood.

I've cut my fingers deeply with a kitchen knife more than once, and bled profusely.

I rarely cook, but I work on cars a lot. Cutting my hands and fingers is part of the routine. Oddly, such cuts have never gotten infected, even when the dirt gets embedded below the skin. I think car grease is an effective bacteriacide!

(I find wearing gloves while working on a car uncomfortable, though I'll do it when cracking a rusted nut loose - when it finally gives way you'll always bang your hand against something.)

That same grease make my cuts all red and inflamed. What gets me is that its rarely jobs that you know will be hard that result in cuts. It's the small simple ones. Switch a ram stick on this beige box, change a set of windscreen wipers. Adjust the temp on the hot water cylinder. Do anything maintenance related to a washing machine.

I don't cut fast and have cut myself a few times to the point of bleeding. Maybe the fact that you cut fast indicates that you are reasonably skilled at this and therefore less likely than others to make yourself bleed, rather than speed indicating that mistakes are more likely.

Reply on news.ycombinator.com