I'm afraid I have no strong hopes on the value of technology to avoid the condemnation of innocents, at least current technology.
I am talking about examples such as these:
1. A person caught in video camera committing a crime such as murder or robbery.
2. A person proved to be involved in rape, from the DNA evidence.
3. A person proved to be involved in crimes such as extortion, as evident from telephone conversations.
In these cases, the judge can be 100% sure about the involvement of the alleged perpetrator in the crime.
One cannot be sure as long as there is the potential for evidence tampering and other sorts of malfeasance. We know that our justice system has some deficiencies by virtue of the fact that different people from different socioeconomic strata get different results among other issues. Once that issue is squared away I'll personally re-visit my support of capital punishment (in practice...in theory I've got no real problem with it.) The thing about capital punishment is that it's permanent and so the machinery needs to be working with extreme precision.
On the other hand, absent a functional capital punishment framework it's more possible that law enforcement will be more incline to play a bigger role than it is supposed to (judge, jury, executioner) and we'll see even more problems in this respect. Already it does seem like there is more police brutality, and I sometimes wonder if it is not becoming something of a policy which is informally filtering downward. If we have another economic issue the cops are going to need every advantage they can get, and having the population being terrified of them is a very effective force multiplier. That's what many countries to do mitigate the numbers issue.