Aborting babies is killing, death penatly is killing a person, even if they did murder. It is still killing someone.
No, abortion is murder. The death penalty is killing. The commandment proscribes murder, not killing. The OT called for capital punishment for quite a few things, including dishonoring one's father and mother. You can make social arguments for and against capital punishment; you can make legal arguments about it, but it's tough to pull one out of the Bible on it.