Ted Kergan would stop at nothing to bring his brother's killers to justice.

It took him almost 30 years and $1 million, but Kergan finally saw to it that the two killers ended up behind bars.

Now Kergan's story is being told in "My Brother's Keeper: A Thirty-Year Quest to Bring Two Killers to Justice," a book written by first-time author Chris Russo Blackwood.

"It was a terrifying, horrific experience to go through," said Kergen of his brother's case that started so many years ago. "I had a really bad feeling right up front and started to prepare myself for the worst-case scenario."

In the book, Blackwood recounts the story that began in 1984 when Gary Kergan disappeared. He was last seen at a Baton Rouge strip club called The Night Spot with a dancer/prostitute known as Erika. In reality, her name was Leila Mulla. Eventually, she and her companion, Ronald Dunnagan, were arrested for Gary Kergan's murder. But his body wasn't located, and then newly elected East Baton Rouge Parish District Attorney Bryan Bush refused to prosecute even though Gary Kergan's car had been found in New Orleans with blood in the trunk.

Ted Kergan offered a $100,000 reward for information to help find his brother, with whom he owned a chain of Sonic Drive-Ins throughout central and south Louisiana. It was the first money spent in what would eventually be a million-dollar quest that included hiring private jets, private investigators and Texas EquuSearch, a search-and-rescue organization dedicated to searching for missing persons, according to the book. Ted Kergen's pursuit of the killers took him from the swamps of south Louisiana and the French Quarter to Las Vegas and New York.

With Mulla and Dunnagan released, Ted Kergan hired private investigators to keep tabs on the two and kept local law enforcement apprised throughout the years.

In 2012, the Baton Rouge Police Department received a federal grant to reopen cold cases, and Gary Kergan's case was chosen. The blood that had been recovered from the trunk those many, many years ago was, through DNA testing of Gary Kergen's son, Wade, proven to be his. Not having a body was no longer a stumbling block.

Because Ted Kergan knew where the two suspected killers were, they were quickly arrested — Mulla in New York, Dunnagan in Bossier City — and brought back to Baton Rouge to stand trial.

Coincidentally, current District Attorney Hillar Moore III was a crime scene investigator on the original case, as was his current investigator, Chuck Smith. 

Mulla was indicted in 2013, pleaded guilty in 2014 to manslaughter and is serving a 30-year prison term. But at the time of Mulla's indictment, an East Baton Rouge Parish grand jury took no action against Dunnagan, according to news reports, and he was released. In the spring of 2014, Mulla implicated Dunnagan, who in 2015 was found guilty of second-degree murder and sentenced to spend the rest of his life in jail.

"This was a difficult case, even with the DNA," said Ted Kergen, giving praise to Moore and prosecutor Dana Cummings. "It took some really courageous people to see it through. It's a testament to Hillar that he let his office take it on."

At the conclusion of the trial, Blackwood, a former reporter who learned of the story through local public relations professional Ann Edelman, put together a book proposal and shopped for an agent. Within a matter of hours, she had one.

"It's about more than a cold case," Blackwood explained. "It gives hope and inspiration to so many … it was an easy story to tell once I got started."

Ted Kergan provided more than 900 digitized documents for Blackwood's use in writing the book.

"He realized, too, that this is an extraordinary story," she said.

Blackwood also talked to Mulla several times in prison.

"She's an interesting individual, but I don't know that I'd believe anything she said. Ron (Dunnagan) wasn't willing to be interviewed," Blackwood said.

"I like to say Leila was the brains and Ron the brawn," said Ted Kergan, who wrote the foreword for the book. "She's a textbook psychopath."

Ted Kergan said he doesn't like the word closure, "but I've gotten to a certain place where I feel vindicated. I made the decision from the beginning I was not going to be a victim.

"At the end of it, I lost one person but I gained so many others," he continued. "I made a lot friends through this that have enriched my life, and I don't say that lightly."

Follow Pam Bordelon on Twitter, @pamspartyline.