Detroit Mayor Mike Duggan asked State Police on Monday to open an investigation into the conduct of Robert Carmack, a city businessman whose agitation campaign against Duggan went public earlier this month.

"No matter how painful the consequences may be, I am not going to give in to these threats," Duggan said in a morning news conference in which the mayor said Carmack had promised to leak embarrassing information about him later this week unless the city settled two lawsuits.

Duggan said he and his family discussed what he called Carmack's threats over the holiday weekend. In the end, Duggan said, they decided that involving the police was in the best interest of the city.

“I wouldn’t be discussing the subject any further except that the events of the last week are making it appear that Bob Carmack is now threatening further embarrassment, in my personal life, in order to force me to take actions that are harmful (financially) to the citizens of the city of Detroit, and I will never allow anyone to force me to act against your interests, no matter what the threats," Duggan said.

Duggan said Carmack on Nov. 7 had promised the city's top lawyer, Lawrence Garcia, that he would "drop a bomb" unless the city agreed to end the lawsuits. Two weeks ago, that "bomb" hit when Carmack paraded a surveillance video around city hall that purported to show the mayor visiting the home of a woman who is not his wife. Carmack, Duggan said, has promised even more releases soon.

“This morning I referred the matter to the Michigan State Police,” Duggan said, adding that he has no idea what type of information Carmack plans to release.

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Duggan told reporters gathered at city hall he would not answer questions of a personal nature because his marriage is among the remaining private aspects of his life.

State Police spokeswoman Shanon Banner confirmed Duggan reached out and said the agency would be meeting with the mayor later Monday to discuss the allegations.

As part of a profile published last week in the Free Press, Carmack said of the mayor: “He’s in for a fight. Don’t mess with the bull, you’ll get the horn. … He’s a suburbian gangster. They don’t fit in in our town. We’ll kick his ass back to Livonia.”

After the mayor's news conference, Carmack provided more information about his discussions with the city's law department to settle his cases involving the city. Carmack said Detroit corporation counsel Lawrence Garcia called him directly — rather than reaching out to Carmack's attorneys — to discuss the cases. Carmack said he doesn't remember saying anything about dropping a "bomb."

"He called me first around my attorneys, and you can't do something like that," Carmack said. "There's a thousand lawsuits, why is (Garcia) reaching out to me directly?"

Carmack provided an email he said Garcia sent him and his lawyers Sept. 21. In it, Garcia thanked Carmack for speaking with him by phone and reminded him that he would be open to "resolving differences out of court."

Several days later, Carmack sent Garcia a settlement offer: $25 million, five licenses to sell marijuana, 30 acres of land on the former site of the Michigan State Fairgrounds and the right to repair all collision-damaged city vehicles.

Garcia rejected the offer, according to emails. He also disputed any improper discussions with Carmack about the case.

When asked why the offer was so outlandish, Carmack said, "I don't ever care to settle with the City of Detroit. I just want the truth to come out."

Carmack also filed a lawsuit last week claiming Duggan does not live in the city as required of elected officials, a claim Duggan vehemently denied Monday morning. The mayor said he and his wife live in the Manoogian Mansion, the official mayoral residence.

"The dog is there, the cats are there, all of our clothes, our furniture, everything in our entire life is at the Manoogian Mansion," Duggan said.

Carmack wouldn't say what other information he plans to release. Carmack said he plans to have a news conference Wednesday to disseminate more information.

“Finally, after 15 years, the truth is finally going to come out of what happened to me in city government with the City of Detroit," Carmack said. "The mayor of Detroit, Mayor Mike Duggan, is scared — scared to death.”

On Nov. 21, as part of an operation for which Carmack said he paid about $20,000, surveillance video of Duggan was broadcast on two giant video monitors affixed to the back of a truck parked outside city hall during the evening rush hour. The truck drove around the government office center, exposing the video to city employees and downtown visitors during the busy evening commute.

The edited video showed Duggan driving to what appeared to be a suburban location and pulling into a garage. On three occasions, according to the annotated production, the video showed a woman arriving at the same location between one and four hours earlier in the day.

The 15-minute video identified the woman and implied Carmack's allegations of an extramarital affair, although nothing in the video provided documentation of those allegations. The Free Press also has not independently verified the accusation.

In a statement the next day, Duggan and his wife, Lori Maher, called Carmack an angry litigant and condemned Carmack's intent to "create a negative judgment on the state of our marriage."

Carmack, who is embroiled in a handful of lawsuits involving the city, told the Free Press he hired a private eye to track the mayor this summer to see whether Duggan was living in the city and to see what the mayor was doing after hours.

Carmack has long held a grudge against Duggan. He blames the mayor for the demolition two years ago of a structure on a piece of property on Michigan Avenue that Carmack believes he owned. The city has disputed Carmack’s ownership, saying it bought the property in 2010 after the county foreclosed on it.

In a separate lawsuit against Carmack filed in June, the city called him a thief for fraudulently obtaining title to a piece of city property and selling it for $1 million. Carmack denies he acquired and sold the property improperly.

Duggan on Monday suggested the June lawsuit prompted Carmack to initiate the surveillance of the mayor.

The video stunt came about a month after Carmack was thrust into the public eye as the key witness in an unrelated bribery case against City Councilman Gabe Leland.

Carmack earlier told the Free Press that Leland extorted him for $15,000. Carmack said he wore a recording device for the FBI in its investigation of Leland, who was indicted Oct. 4 on bribery charges.

Leland has pleaded not guilty to the charges.

Joe Guillen is a reporter on the Free Press Investigations Team. He has been covering city governance and development issues for the newspaper since 2013. Contact him at 313-222-6678 or jguillen@freepress.com.

To read more on Carmack, Leland and other Free Press investigations, go to www.freep.com/news/investigations. If you have a tip that should be investigated contact us at investigations@freepress.com.