DETROIT (WWJ) — It will take time, patience — and money — for Wayne County to investigate billionaire Dan Gilbert’s Rock Ventures offer to Wayne County for the much-contested downtown county jail site.

“This is a tremendously complex proposal,” Wayne County Executive Warren Evans said during a Monday morning press conference, adding, “We need to spend money to get it right.”

Evans would not put the county’s response on a timeline. He did request that the Wayne County Commission approves a $500,000 cost to pause construction and have Walsh Construction study the offer and create a county proposal.

Rock Ventures submitted an offer to Wayne County to basically swap the high-profile site of the current jail under construction for a new, state-of-the-art, consolidated criminal justice center Rock Ventures would build for the county. It would include a new adult and juvenile detention facilities and a new criminal courthouse that would replace the current Frank Murphy Hall of Justice.

Rock Ventures would turn the current construction site downtown into a $1 billion commercial development, which would potentially include a Major League Soccer stadium.

Rock Ventures says it would build the project with $300 million from the county, the cost that has been estimated it will take to complete the jail project.

Rock Ventures says it would spend an estimated $420 on the new jail complex. But Evans added he has doubts that offer will be enough to build a jail facility that meets the county’s needs. And there are questions about who pays for overruns, and whether jail bond proceeds can be used for building on an alternative site.

There’s also a question about the savings credit Gilbert is requesting from the county as part of the deal. Rock Ventures’ offer says the credit is to be calculated based on the difference between the estimated costs to operate the Gilbert-built criminal justice complex and the estimated cost to operate the county’s jail if they finished the existing site. That amount is unknown.

“I’d just like to make the understatement of the year — I agree with Dan Gilbert that this is a 50 year decision, but it’s important to remember that we’re nearly a decade into this debacle,” Evans said.

Last April, billionaire Gilbert revealed sparkling plans for a brand new professional soccer stadium on the downtown Detroit site, which he didn’t own and the county said at the time it didn’t plan to sell it to him.

Gilbert’s plan included restaurants, offices and hotels, in addition to the 25,000-seat Major League Soccer stadium.

The proposed site of the new criminal justice complex is located at E. Forest Ave., east of I-75, approximately 1.5 miles north of the current Gratiot Avenue site.

Gilbert said he met with Evans, Detroit Mayor Mike Duggan and others last year to discuss a possible deal, offering $50 million for the jail site. That was apparently a non-starter.

“We have worked hard to develop and deliver to the County a proposal that, we believe, will be the best long-term outcome for the County and for the future of downtown Detroit. Specifically, we will deliver to the County a modern, consolidated criminal justice center with no risk and at the same dollar amount they estimate it would cost them to complete the project on Gratiot,” said Matt Cullen, principal of Rock Ventures, when the new plan was announced.

“In addition, we are prepared to build a development on the Gratiot Avenue Site, located in the heart of the sports and entertainment district, that will provide significant economic impact and that Detroiters will be proud to have at the ‘front door’ to the city,” adds Cullen. “We respect the County’s process and look forward to working side-by-side with Wayne County Executive Warren Evans and the County Commission to do the necessary analysis to validate the assumptions in the offer.”

Evans clearly understands public frustration with the failed jail, saying during the presser, “It’s been the albatross around the county’s neck for way too long,” and adding the current jail project has “taxpayers’ dollars buried in the ground.”