The case of a nearly 29-year-old murder is being reheard by a jury in Fulton County.

Curtis Tyner was 36 when he admitted to raping and strangling IBM executive Martha Ann Mickel in April 1984.

But because the Georgia Supreme Court found in a 2011 appeal that he wasn’t appropriately informed of his rights when he confessed to police, without the counsel of an attorney, the conviction was thrown out.

Now, Fulton prosecutors are trying the case again rather than risk letting Tyner free from what was a life prison sentence.

“He said, ‘I might have killed her,’” retired Fulton County police Detective John Lines testified Wednesday, reading the transcript of one of his interviews with Tyner to the jury.

Mickel’s body was found floating in Bear Creek in south Fulton County. A medical examiner determined she had drowned, but pointed to ligature markings indicating that she had been tied around the neck to her automobile’s headrest.

Her hands were tied, the buttons to her blouse had been ripped off and her pants were open.

Tyner told police that when she slumped over in the car, he thought she was dead and panicked. He said he threw her in the river, not knowing she was still breathing.

The former painter, who had been hired by Mickel to paint her Smyrna condominium, is being charged with murder, felony murder, kidnapping with bodily injury, aggravated assault with intent to rape, robbery by force and sexual battery for the death of the 30-year-old Mickel.

But in the June 2011 Supreme Court decision that reversed Tyner’s fortune, Justice David Nahmias pointed out that no one fully informed Tyner of all the rights he was waiving when he made his guilty plea.

“The record does not show that Tyner was advised of his right against self-incrimination,” Nahmias wrote in the opinion. “His guilty plea was invalid and we must reverse his conviction.”

A transcript from the original plea hearing showed that neither the judge, the prosecutor nor the public defender explicitly explain to Tyner his right not to self-incriminate.

Instead of letting Tyner go free, however, the Fulton County District Attorney’s Office took the unprecedented step of indicting Tyner again, and by January 2012, he was returned from the Wilcox State Prison to the Fulton County jail to prepare for the new trial.

There is no double jeopardy in this case since Tyner was the catalyst for the verdict change, UGA endowed law professor Ronald Carlson said.

“If the retrial is the result of creative action by the defendant, double jeopardy is ruled out,” Carlson said.

One of the challenges apparent for either side in this trial is the advent of DNA, he said.

“Now, an old conviction can be restored in situations where new forms of DNA testing make up for lost witnesses,” Carlson said.

Tyner’s attorney Angela Clarke broached the issue as she cross-examined Lines, questioning the rape or attempted rape allegations.

“There was no evidence of semen from the (GBI) Crime Lab, was there?” Clarke asked.

“I don’t believe we ever got anything back from the Crime Lab,” Lines responded.

Carlson pointed to another difficulty prosecutors face trying a nearly 30-year-old case.

“Retrials are very difficult after more than two decades,” Carlson said. “In the typical case, witnesses have died and evidence may be lost over the passage of time. Witnesses who remain may sometimes have only distant memories of the critical facts.”

In court Wednesday, prosecutors trotted out witnesses who in many cases needed to have their recollections of events and statements refreshed.

“Did he ever tell you how he got the rope?” assistant Fulton County District Attorney Sheila Ross asked another retired Fulton police detective, Paul Taylor.

“Yes,” Taylor replied, before reading from a copy of his original investigative report, now part of evidentiary files.

Tyner’s attorney, Lamar Rhodes, challenged former detective-turned-Kennesaw State University officer J.D. Shirley on his recall.

“It’s been 29 years,” Rhodes said. “You had to be reminded (on the stand) of the day you surveiled Mr. Tyner’s home … but you can remember what the rope looked like that he used?”

Lines read more from the typed statement Tyner signed days after Mickel’s April 15 disappearance.

In the confession, Tyner suggested that he somehow blacked out or lost track of time.

“‘I left my home and drove to where Martha lived,’” Lines read aloud. “‘Next thing I know, I was going south on I-285. That’s when I realized that Martha was with me and her hands were tied and rope was around her neck.’”

In the statement Lines read, Tyner told police he pulled over and cut the rope from Mickel, then threw it out somewhere between Cascade Road and Washington Road. Then he turned south on I-85 and headed somewhere near Palmetto.

“‘I came to a bridge … and threw her purse out,’” Lines said, reading Tyner’s words. “’I stopped at (another) bridge and threw her body out.’”

Lines told the court that Tyner was able to direct police to where the purse was tossed.

“Only the person who killed Martha Mickels and threw her purse in that creek could know where the purse was,” he said.

Court adjourned and the jury was dismissed late Wednesday afternoon.

The trial will resume Thursday with the final witness for the prosecution.