Cook County prosecutors Wednesday said they will take R. Kelly to trial on charges related to his alleged sexual assault of a hairdresser who said she was attacked during a 2003 appointment with the R&B singer.

The criminal case will be the first among the four cases filed in Cook County last year against Kelly to go to trial and is the only one involving a victim who was not a minor when the alleged crime took place. Judge Lawrence Flood previously set a trial date for Sept. 14.

Kelly is also expected to stand trial in federal courts in New York and Chicago this spring.

The hairdresser in the Cook County case — listed in court records as “L.C.” — came forward publicly in March, identifying herself as Lanita Carter. Carter said she was 24 when she was assaulted by Kelly after she went to his Near North Side home to braid his hair. Carter, in interviews, said she reported the attack immediately but no charges were filed.

The other three women tied to the pending cases filed against Kelly in Cook County said they were under 16 when they were assaulted.

Kelly was not in court for Wednesday’s hearing. Attorney Steve Greenberg, said Kelly, who is being held at the federal Metropolitan Correctional Center downtown, had a medical procedure and was not able to make the trip to court. Talking to reporters after the hearing, Greenberg would not elaborate on Kelly’s condition, other than to say that Kelly was recuperating and was expected to be fine.

Greenberg downplayed Carter’s case against his client, noting that prosecutors declined to bring charges against Kelly when the alleged victim first reported the incident nearly two decades ago.

“[The case] hasn’t gotten any better. It’s not like wine, it doesn’t get better with age,” Greenberg said.

Greenberg said he had seen some of Carter’s interviews with various media outlets, and would review those public statements with what she has told police and prosecutors.

“There’s a reason why they didn’t bring this case many years ago, and there’s problems with the case, and there’s good things and there’s bad things,” Greenberg said. “All these people come with baggage and we’ll let the jury know about that baggage.”

At Kelly’s bond hearing last year, prosecutors said when Carter met Kelly for his hair appointment, he greeted her with his pants pulled down and said that he didn’t want his hair braided but wanted his “head massaged.”

Kelly allegedly ejaculated on the woman and spit in her face several times. The woman turned over a stained shirt to investigators, that had DNA from Kelly’s semen on it.

Prosecutors’ decision to take this case to trial ahead of any of the other three indicates they believe it has the strongest evidence against Kelly, said veteran defense attorney Tony Thedford.

“There’s no magic to it. The state can elect on any case, and they pick the one that they think has the fewest obstacles, that they think is the easiest one for them to prove,” Thedford said.

Key to the decision was the fact that Carter went to police immediately, and provided them with DNA evidence of some sort of sexual contact with Kelly, Thedford suggested. Prosecutors also are likely to try to introduce evidence of alleged sex crimes involving others — whether they are victims in the other three cases, or incidents that have never been charged — at trial, Thedford said.