Something has to be done. It's a refrain that is pulled out after every latest outrage committed by hardened criminals. Whether it is the brutal murder of an innocent, evidence of witnesses being intimidated, or any of the many manifestations of gang crime. Something has to be done.

The impulse to do something is entirely understandable, no more than an impulse to perpetrate violence on somebody who has harmed a loved one. But while an individual might be moved to act on impulse, those charged with the rule of law are obliged to act coldly, proportionately and with a modicum of intelligent design. The objective must be to impact on the incidence of crime through effective measures while retaining proper standards of the rule of law. When standards drop, the criminals are winning.

In recent years, "doing something" in reaction to growing crime has largely involved a public-relations exercise, in which a minister for justice declares he is going to "take on" the criminals by introducing laws that sound tough, but do little to tackle the problem.

The latest of these moves, the Criminal Justice (Amendment) Bill, should really be called the Something Has To Be Done Bill. As a piece of legislation, it is top heavy with headline-grabbing items, the sort of stuff that gives the impression that an effective response has been fashioned to "take on" criminal gangs.

The bill is being rushed through the Oireachtas to ensure, against all best practice, the minimum of debate and examination. Too much probing might puncture the thin veneer of PR in which the measures are wrapped.

In reality, the bill will have little or no impact in tackling gang crime. It is entirely a political manoeuvre. But it won't generate outrage on Liveline, and that is one of the key determinates of policy making these days.

The bill presses all the right buttons. It sounds tough. The measures are easy to digest. For example, mention of the non-jury Special Criminal Court tells the average citizen that these gang criminals will be dealt with in a different manner from ordinary defendants. That's enough for most people to nod sagely and declare that at last the government is getting tough on crime.

Provision already exists for the DPP to refer gangland cases to the Special Criminal Court if he feels it necessary. The minister, Dermot Ahern, obviously believes the DPP doesn't know what he is doing. Ahern thinks he knows better than those working at the frontline.

Every time the minister is asked about the requirement for non-jury courts, he brings the debate around to witness intimidation, which happens in all courts, including the Special Criminal Court.

Ahern cynically uses the brutal murder in Limerick of Roy Collins to push his agenda.

"The murder of Roy Collins means that new legislation was required. The state had to respond," he said on Morning Ireland on the day after publication of the bill. Roy Collins was shot dead because his cousin bravely gave evidence in court against gang criminals. It had nothing to do with jury intimidation.

The minister didn't stop there. He inferred that the reaction of Roy Collins's bereaved father Steve had an influence on the framing of the legislation.

"You only had to listen to Steve Collins," he told the programme. "Whatever doubts I had prior to that, meeting him and his family dispelled those doubts." Ahern cynically feeds the impression that he is elevating a victim of crime to the status of lawmaker, thus feeding woolly populist notions more suited to Saudi Arabia.

The Collins family must be extended every support by the state. They are owed an enormous debt, but unfortunately the horror that befell them as a result of their bravery would have been no different if the case in question was heard in the Special Criminal Court.

What the new law does is undermine the basic right to a jury trial. One up for the criminals who want to dismantle the rule of law. Notably, even prosecuting lawyers, charged with bringing these people to book, have come out in protest at a dangerous departure from a fundamental right.

There is no evidence of jury tampering in the state. When it is deemed necessary, trials are moved from Limerick to Dublin to facilitate jury selection. Judge Paul Carney, the country's leading criminal court judge, has referenced the robustness of the jury system. Yet Ahern, in the absence of any evidence to support his case, thinks he knows better off the top of his head.

Elsewhere, the bill introduces the spectre of a garda of any rank presenting the court with opinion evidence regarding gang crime. Go down through the long litany of miscarriages of justice in this state – including the Kerry babies case, Nicky Kelly, Nora Wall, Dean Lyons, the McBreartys, Frank Shortt – and in each of these cases the basis for prosecution was gardaí of ordinary rank forming an erroneous opinion on the guilt of the accused and then seeking out the evidence to back up his opinion. (In McBrearty and Shortt there was also blatant corruption.)

Under the new bill, a garda harbouring an erroneous – or a corrupt – opinion no longer has to even find evidence to back it up. He just trots into the court and tells the judge this is his opinion, which the judge is obliged to consider.

The measure will heighten the dangers of further wrongful convictions. Those with most to fear from this stuff are not the gang leaders or hardened thugs. Innocent young men, whose only crime is to grow up in the neighbourhoods where these gangs prosper, will find themselves in danger from excessive powers being granted to the police. Concern for their rights may not be fashionable, but why should they be sacrificed on the altar of cheap political point-scoring?

Again, the criminals win. The moral authority of the rule of law is undermined. Of course, on cursory examination the measure sounds tough and that's what it's all about. Something, anything, is being done.

The measure on secret detention hearings for suspects resonates more with Guantanamo Bay than a functioning democracy. Are we really conceding that we have failed as a society to the extent that our laws measure up against those usually the preserve of tin-pot dictatorships?

The notion that merely signing in new laws will impact hugely on the complex and societal problems of gang crime is ludicrous. Resources are vital, but resources face cutbacks, and Ahern needs political cover for the day when the money runs out.

Rare sensible legislation also helps. The new law on surveillance evidence will be valuable. Last week's sentencing of double murderer Gary Campion highlighted the value of the law on witness intimidation, in which statements made soon after the crime can be considered even when a witness refuses to testify in court.

But those measures are already in place. Ahern needed "something" new to show that he is a tough guy taking on the gangs. He needed something to ensure that Fine Gael couldn't shout that he is soft on crime. He needed something to deflect from the ineptitude of government in other areas. He needed something that wouldn't be challenged on Liveline.

He got it. As a PR exercise, the Criminal Justice (Amendment) Bill is a fine piece of work. As a declaration of where the state stands, it degrades the notion of proper standards of the rule of law. It's one up for the criminals. We are embarking down their road.