Why doesnt Ireland electronically tag violent criminals If they intend to grant them bail?

Well, note that the object stated in the OP is to afford us "protection from threat", whereas the aim of the prison service experiment seems to have been so save money.

Let's think this through. Obviously, in themselves, electronic tags do not provide any protection. If I am murdered by a man wearing an electronic tag, I am just as dead as if I had been murdered by a man without one. The tag itself does nothing to protect me.

The idea that it protects me is based on some unstated assumptions:

• The many is already known or suspected to be a dangerous violent offender.
• He has come to the attention of law enforcement for that reason, and has become subject to the legal process.
• The legal process has applied rules or restrictions to him to restrain his violent offending.
• Those restrictions include restrictions on where he is permitted to go, or where he is permitted to be.
• Those restrictions, if observed, will actually be effective to reduce his violent offending
• Electronic tagging will assist in enforcing observance of the rules and restrictions.

There's a lot of assumptions that can go wrong in there, and if any of the prior assumptions do go wrong, then tagging is not going to fix the problem. It seems to me that tagging really only helps if bail restrictions are appropriate and are well-targeted, and if tagging assists in enforcing them more effectively, or more cheaply.

Tagging might be effective but expensive. For example, prisoners being released to go to hospital; you can tackle the risk of them absconding by sending a prison officer to accompany them, or by tagging them (which doesn't directly prevent them from absconding, but means that if they do they can be recaptured reasonably quickly, which in may make it less likely that they will abscond in the first place and limits the opportunity they have for further offending if they do abscond.) On the face of it, sending a prison officer seems likely to be more effective at preventing absconding and further offending. If it also turns out to be cheaper, that decision is a no-brainer.

Because they have not been convicted of any offence, and may in fact be wholly innocent?

Yes, they can. But the presumption is in favour of bail; you need a good reason for denying them bail. And the good reason can't be punishing them on account of the crimes with which they have been charged, since we do not know if they are guilty of those crimes. The mere fact that someone has been charged with violent offences does not establish that he is a violent person and does not allow us to restrain him on the basis that the is a violent person.

Good reasons for denying somebody bail would be things like:

• Concrete reasons for supposing that he will abscond to avoid trial (rather than the abstract fear that he could do so, which would apply equally to everyone accused of any offence)
• Concrete reasons for thinking that he will interfere with witnesses, or otherwise attempt to interfere with his own trial
• Concrete reasons for thinking that, if bailed, he will commit serious offences.

At least in principle, electronic tagging could have a role to play in preventing people from absconding (since it makes it easy for you to find them), so electronic tagging of somebody who presents a flight risk could be an alternative to refusing them bail. But I don't know how realistic this is in practice; you'd want to be pretty confident that the electronic tag couldn't be removed, and in the real world I don't know if we can be that confident.

Tagging might have some role in policing a "don't interfere with witnesses" condition, if it took the form of, e.g, "stay away from your ex". Note that I say "policing", not "enforcing". A tag won't stop the accused breaching this condition; it will just mean that we will know if he breaches it, and we can punish him for it after the event. And that might discourage the breach in the first place so, yeah, it could have some role there. But keep your expectations realistic; this may reduce the incidence of people breaching "stay away from . . ." bail conditions, but it won't eliminate it.

Same goes for conditions designed to stop anticipated offences; my gut says that tagging will probably be more useful in detecting and punishing breaches of those conditions than in preventing them.

Part of the problem here is that a lot of people who end up in the criminal justice system have poor impulse control, and/or are not good at allowing foresight of the consequences to influence their actions; that's why they end up in the system. You and I might think that the prospect of being detected and punished for theft, or assault, or whatever, would deter us from stealing or assaulting, but that's not the reason we don't steal or assault, is it? We don't go around constantly suppressing a desire to take stuff or hit people by reminding ourselves that, if we do, we'll go to prison; other factors explain why we don't do this, so we are not living proof of the efficacy of the fear of detection/punishment as a deterrent.

My gut says that crimes that are committed in a calculating way - like fraud, systematic theft, that kind of thing - may well be deterred by improved methods of detection and prosecution, and in circumstances where electronic tags can improve detection and prosecution of these crimes, they might be beneficial. But crimes that are committed on impulse, crimes that exhibit a lack of control - and I think we are talking here about a large proportion of crimes of violence - are a different story. Somebody like a professional hitman might be influenced by a cost-benefit analysis of the risk of detection, but very few murders are committed by professional hitmen. Most murders are committed by family members who aren't thinking rationally at all, or they are completely unplanned, the outcome of unexpected confrontations that escalate.

Tl;dr: I'm not saying that electronic tagging has no useful role to play in preventing crime. But you need to think very carefully and dispassionately about the circumstances in which it will be effective, which I suspect are quite limited. The fact that electronic tagging is widely used in the US or the UK does not mean that it is effective; law enforcement policies in most democracies are a blend between what actually works and what plays well in the tabloids, and widespread tagging could easily be employed in those countries because voters like it, and assume that it works, rather than because it actually does work.

In the context of bail, which is the issue raised by the OP, wider use of tagging would probably lead to more grants of bail, not fewer. If tagging is seen as effective in tackling absconding, reoffending, etc, then you don't need to remand people in custody to prevent these things; you can bail them with tags. More liberty for people accused of crimes and a much, much lower cost to the state; what's not to like? So that's what would happen.

The title to the thread refers specifically to people who are granted bail. My apologies if I misunderstood you.