CHICAGO (CBS) — The new leader of Illinois House Republicans said Mayor Rahm Emanuel’s push for tougher penalties for gun crimes could be a good thing, but also expensive.

WBBM Newsradio Political Editor Craig Dellimore reports, as a former prosecutor, State Rep. Jim Durkin (R-Western Springs) agreed with the mayor’s goal of a mandatory three-year minimum sentence for illegal gun possession.

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“I probably have a perspective that’s a little different than most of my colleagues, of working in a high-volume courtroom at 26th and California, in Chicago – one of the most active courthouses in the United States – and I’ve seen my share of gun violence,” he said.

However, he said lawmakers also must consider the cost of putting more people in state prisons and county jails.

“Increasing the penalties for a firearm to a non-probational offense, it will have an effect on our county jails,” Durkin said, “What will happen is that when a bond is set for an individual who is charged with an offense that is non-probationable, naturally a court is going to set a higher bond. That means a lot of the individuals will not be able to bond out.”

Emanuel and his police superintendent, Garry McCarthy, aren’t buying the idea that mandatory minimums will automatically cost taxpayers more in the long run.

Right now, it costs more than $21,000 a year to house an inmate in an Illinois state prison. State officials say eliminating the possibility of probation will put even more people in jail. Locking up everyone caught with a gun and now given probation could run $130 million a year.

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Not necessarily, says McCarthy.

“It’s reality that if you have a gun you get arrested go to prison significant time there. It that’s the understanding, people are going to stop doing it,” he says.

Proposed legislation requires jail time for anyone except a first-time offender with no record and no gang ties and that they serve at least 85 percent of their sentences.

Durkin said the court system already is very crowded, and authorities would have to find more bed space in jails and prisons for the additional influx of inmates that would result from tougher gun penalties.

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He is the guest on WBBM’s “At Issue” program this week, airing Sunday at 9:30 a.m. and 9:30 p.m.