Wayne County Executive Warren Evans plans to put competing proposals for downtown jail and criminal justice facilities from Walsh Construction and Dan Gilbert's Rock Ventures LLC on dual tracks as his administration evaluates the best deal for taxpayers.

Evans said Wednesday that the county will issue a request for proposals to Chicago-based Walsh Construction for restarting construction of the half-built jail site on Gratiot Avenue while officials scrutinize Gilbert's alternative plan of building a criminal justice complex on existing county-owned land on East Forest Avenue.

"I want to be able to see what the best opportunity to get what we need at the least cost to taxpayers as soon as we can," Evans said in an interview with Crain's.

Rock Ventures proposed building a $420 million county jail, juvenile detention center and new courthouse on the East Forest Avenue site east of I-75 in exchange for $300 million, the half-built jail site, the Frank Murphy Hall of Justice, two old county jails and the county's juvenile detention center.

The proposal from Gilbert's real estate development company came four days before Evans' deadline for issuing the RFP to Walsh.

Evans said he's going to study both plans because the county could be four months away from actually signing a construction contract with Walsh.

"I think we'll know in that time frame," he said.

In the meantime, Wayne County may need to pay Walsh to go through the design and engineering RFP process with the possibility that it won't get the job, Evans said.

"That's something we're considering," he said.

It's an unusual situation because Walsh is the only company competing for the contract to finish building the jail, but could still lose if the county decides to pursue the Rock Ventures proposal.

"If there had been bidders, we'd be sending out RFPs to more than one person," Evans said.

A Walsh Construction representative could not be reached for comment Wednesday.

Evans said he'll ask the Wayne County Commission to authorize him to hire a consultant to evaluate the Rock Ventures proposal.

View: Rock Ventures' 34-page proposal to Wayne County for jail sites

Some county commissioners have expressed initial skepticism about Gilbert's plan — a sentiment Evans shares about the price tag.

"I'm not in the construction business, but $420 million sounds like kind of a small number to me to be able to create three new buildings if those buildings are going to be like I think we'd like them to be," Evans said.

Under the Rock Ventures plan, the jail would not be as big as Wayne County officials had wanted in an effort to consolidate three county jails in Detroit and Hamtramck under one roof.

The half-built jail on Gratiot Avenue was supposed to have 2,000 beds. Gilbert's plan promises a 1,600-bed jail. But for an extra $43 million, the county can add another 400 beds to the jail, according to Rock Ventures' proposal.

"If I had the money to build the other 400 beds, I certainly would do that," Evans said. "... The best, cheapest deal for Wayne County is the deal we're going to take."

One area of early contention is the Rock Ventures proposal calls for a $300 million payment plus an undefined "operational savings credit" for money Wayne County would save with the consolidated criminal justice facilities.

Gary Woronchak, chairman of the Wayne County Commission, called the credit "mumbo jumbo" and a potential unforeseen financial cost with which he'd rather not saddle the county.

Madeline Chadwick, vice president of communications for Rock Ventures, said the proposed operational credit realized through the efficiency of a new courthouse versus an older building like the Frank Murphy Hall of Justice would be subject to negotiations with the county. Rock Ventures doesn't have a particular dollar amount in mind, she said.

"It's not really defined yet because this is just an initial offer," Chadwick said Wednesday.

The Rock Ventures proposal set a Feb. 20 deadline for the county to engage.

Officials at Gilbert's real estate company are awaiting a response from the Evans administration about whether they "want to move forward," Chadwick said.

"We haven't heard anything from the county," she said. "We're giving them time to review it and waiting to hear back."