Even if you, few jurors are likely to be. So they have to rely on what they're told by other poeple. Other people, including specialist witnesses, are sometimes mistaken or deceitful, or didn't you know?

Yes, mistakes are made due to the factors you mention above, which is why i said capital punishment should only be implemented when it is proven via DNA evidence. Restoration of capital punishment for paedophiles, terrorists and murderers should be an option for judges in cases where their guilt is proven beyond dispute, as by DNA evidence or being caught red-handed.