Given your support for abortion, any claimed concern in this case about “killing an innocent person” is a hollow joke.
The one to be executed has first been through the very best process we can devise to establish that he has, in fact, committed a crime of sufficient severity to call for putting him to death. Whatever flaws may exist in that process, whatever errors it may occasionally produce, it is still far better than what the victim of an abortion gets before he is put to death without ever having even been credibly accused of any crime.
And far more innocent human beings are put to death via abortion, by several orders of magnitude, than all who are put to death by judicial execution, even counting those who are guilty.