A fellow inmate, Declan O'Reilly, from Parnell Road in Crumlin, Dublin, has been charged with Glennon's murder and has been remanded in custody.

In the days that followed Glennon's death, the Prison Service transferred some inmates to other jails and granted early release to 14 other prisoners, something it denies is linked to the tensions that have followed the death, but which obviously will help to reduce the teeming and tense overcrowding in Mountjoy.

At the time of Glennon's death, there were 568 prisoners in the jail, 88 more than the 480 limit to which the government is committed. The claustrophobia in the prison, in which small, unsanitary cells are shared, is evident.

The full facts of the case will be heard in court and two investigations have begun.

The violent attack on the Crumlin home of a relative of the accused man demonstrates how quickly events can spiral out of control outside the prison walls.

The problems in many of our prisons, and in Mountjoy in particular, are clear to all, and have been for years. There have been repeated warnings since the brutal killing of prisoner Gary Douche in August 2006 that it was only a matter of time before there was more violence. Tragically, Derek Glennon is now dead.

The day after his killing, new justice minister Brian Lenihan announced a series of measures to improve the security of our prisons.

These include the establishment of a special squad with powers to search visitors, inmates and their cells, as well as a sniffer dog unit to counter drug-smuggling into prison. There will also be new x-ray screening for everyone - prisoners, visitors and staff - going into prisons and there is to be a segregation unit for gang leaders suspected of directing crime from behind bars.

While all of these initiatives are welcome, the real surprise is that they are not already common practice. The abuse of drugs in Mountjoy is now so widespread that the public is no longer interested in it, let alone outraged by it. It is common knowledge that gangland bosses exert malign control within prison by intimidating inmates with violence and threats, and that they control gang members on the outside using forbidden mobile phones.

With many of the wrongs in society, sometimes we accept them because they're part of the everyday - we see them, hear of them and experience them so often that they fall off the reform agenda. This is what has happened with our prisons. We accept the totally unacceptable in terms of dire prison accommodation, facilities, education, training and drug rehabilitation because it has always been that way. Because only criminals and drug addicts are affected, there is no public or political will to pay for reform.

But allowing security to lapse in prisons is not a "humane" response to lack of facilities.

If anything, it worsens the crisis as the inmates who are addicted to drugs, or who are victims of bullying and violence, will attest.

The replacement for Mountjoy, Thornton Hall, is scheduled to be completed by 2011, though the Environmental Impact Statement that it may now require will no doubt delay its opening. It has been argued that non-custodial community sanctions would be preferable to building a new prison. The public does not want this - in fact they want the exact opposite in the form of longer sentences and a tougher regime.

But a big modern prison does not have to bring with it a repetition of the wrongs of Mountjoy. Proper security to keep the drugs and weapons out, coupled with adequatelyresourced education and drug rehabilitation, are vital if we are to allow inmates to serve their sentences with a modicum of dignity.

More importantly, education and support for prisoners may give them more choices when they're released to help them stay out for good.