You make it sound like if the death penalty is removed then people that are meant to receive the capital punishment will be set free. If you escape the death penalty then the next thing that follows is life imprisonment.
How can the person commit the crime again if they're behind bars??
Secondly your logic is flawed,you make it sound like people that commit murder and are convicted receive jail time, are let out, get convicted again, receive more jail time, are let out and do the same thing again but if you're a second offender for a crime like murder, it's either death or life imprisonment. You also didn't mention the gravity of the offence which would require a person to be put to death, but I assume it's murder. If a person commits murder and is convicted of it then sentenced to death and it's miraculously overturned then the person isn't going to leave prison, I'm pretty sure people like that get life sentence without the possibility of parole and that means their never getting out.
Oh and what happens when a person is actually innocent of the crime?? Do they get justice from the grave??
Going by your logic, if one person is given the death penalty then it reduces the total number of people that commit crimes and thus the crime rate reduces as well but if they're in jail then how are they supposed to commit these crimes??? Yes prisons are overpopulated but does that mean that we should solve it by handing out death sentences like their gift cards????
Finally, this question was
Should death penalty be implemented across the globe? ?
Do you think its presence will reduce crime rates? What would be the standard to condemn someone?
Going by your logic, its presence reduces crime rates, and going by that same logic so does life imprisonment. I'm not against the death penalty or anything, but if we're using it to reduce crime rates, then I don't think it's the best way forward, all you're doing is taking a life, maybe it's one that deserves to be taken, but as far as the crime rate goes, it won't affect it in anyway.