Picture this: you're tottering home from the pub in Ennis, when you're overwhelmed by a call of nature. You run down a sidestreet and relieve yourself. Suddenly there's a loud buzzing, an electrifying flash and your nether regions light up like a Christmas tree. The owner of the shop you're peeing on – in this case Custy's music store – has installed an electric fence to stop people like you interfering with his property.

Conclusion? You won't do that again in a hurry.

It's a basic principle: your actions have consequences. The same applies for inaction too. Justice minister Dermot Ahern is today facing the consequences of his inactions. The latest CSO figures show that aggravated burglaries have increased by 51% this year and that 'ordinary' burglaries rose by 27% between July and September.

Shocking figures aren't they? Well actually, no, they're not. It's another basic principle: recession means that money goes down and crime goes up. Ahern has been expecting these figures.

Here's another figure Ahern is aware of: 25% of all serious crime is committed by people on bail (CSO, 2008). Prison overcrowding leads to more people on bail. This leads to more crime. Ahern admitted as much on 8 April when he told reporters that he couldn't tighten the bail laws because of overcrowding. There wasn't enough room to keep potentially dangerous suspects behind bars.

So what exactly has he done about overcrowding? Has he forced through the construction of Thornton Hall prison? You know the answer to that. In total, €40m has been spent on the project, with the government paying well over the odds for the site. Instead of turning the sod there, Ahern has been planting shrubs. The latest bill for Thornton Hall is €18,000 for gardening. Its maintenance has cost us €440,000 so far. Instead of a prison we have a well-groomed parkland.

Meanwhile, there's a burglar downstairs who should be behind bars. Get angry about it – but not too angry, if you don't want to get sued. Ahern won't amend the laws to allow homeowners to tackle burglars without being liable for injuries they receive. Or shop-owners. How soon before Custy's of Ennis is sued by some crotch-clutching moron?

The most credible long-term attempt by Ahern to deal with overcrowding was the introduction of the Fines Bill 2009. This allows for alternatives to custodial sentences for loan defaulters. In the past year, almost 300 people were jailed over unpaid debts. As more people lose their homes, more will go to court. More overcrowding, more bailings, more crime. Guess what? Like Thornton Hall, the bill is still at the talking stage. Ahern's detestable Blasphemy Bill made it into law before something that will alleviate needless suffering.

Along with these unfortunate prisoners, the jails will also have to accommodate a new brand of criminal – the Recession Burglar. A rising crime rate means more people heading to jail. With the traditional Christmas burglary spree coming, the situation can only worsen, putting more pressure on the system.

The Department of Justice is operating a revolving door which is spinning out of control. Last year, anyone serving under 20 months in Mountjoy's Dóchas unit was released to make space for more serious offenders. During the summer, overcrowding led to a huge increase in the number of offenders on temporary release. On 29 May, 14.65% of the prison population were at temporary liberty, compared to 8.75% in January.

Recidivist criminals have murdered while on bail. Last April, days after Ahern announced his Fines Bill, Gerard Barry was convicted of the rape and murder of Swiss teenager Manuela Riedo. He had been out on bail.

Ahern says that new beds recently provided across the service will deal with current overcrowding. As crime figures rise, they will not be enough.

Thornton Hall will not be ready for years, therefore other solutions are needed. One is the immediate implementation of the Fines Bill. Another is the reopening of the prisons closed by Michael McDowell. Their gates were shut because he expected Thornton Hall to be operational by now.

We must protect society and show compassion to prisoners. This can only be achieved with a functioning system, where custodial sentences are respected and inmates' rights are protected.

Jail must not be hell on earth – but it should be a deterrent. Wrongdoers – as the man urinating against Custy's shop discovered – must know that there are consequences to their actions.

Finally, there might be another way of dealing with Thornton Hall. It's a classic toxic asset, bought for too much money by the state. (See where I'm going with this?) Perhaps Nama has the answer. Maybe it can get it built by giving it away to a developer as a 'bonus buy'. "We'll even throw in this fully landscaped, rural idyll, with permission for a 1,400 bed guest house and several bars… on the windows."

If we continue to just plant flowers on it, we'll reap the whirlwind. In the meantime, Ahern must deliver credible alternatives to deal with the crime upsurge.

On a brighter note, there's one positive revelation in the new CSO figures. There's been no rise in the number of aggravated blasphemies. Nice work there, minister.

dkenny@tribune.ie