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Mastermind of Murder: The Volatile and Tragic Marriage of Alan and Dianne Masters

I'm a Tennessee-based freelance writer with a passion for true crime, a thirst for knowledge, and an obsession with lists.

Dianne Masters

Dianne Masters

Dianne Meets Alan Masters

Dianne Turner Mueller was a married woman when she met Alan Masters in January 1969. Her husband, Ronald Mueller, was serving in Vietnam when she met with the divorce attorney. She’d already had a few affairs while Ronald was away—undoubtedly a large reason for the divorce, but none would become so serious as it did with one of Chicago’s best-known lawyers.

From the very beginning, Alan, 11 years Dianne’s senior and also married, wooed the young woman with his money, buying her fine clothing and jewelry as well as flower deliveries and daily phone calls. It was everything Dianne had ever dreamed of: fancy homes, flashy cars, the latest fashions. And the parties they hosted were amazing; the guest lists always sporting the names of Chicago’s elite and well-connected.

For several years, Dianne was willing to be Alan’s mistress. She accepted being secreted away, a secondary thought to Alan’s “first” family, and served as an outlet for rages, which often culminated in physical violence. By 1974, after getting pregnant resulted in Alan forcing her to have an abortion instead of leaving his wife as she had hoped, Dianne was getting tired of it all, so she gave Alan an ultimatum: Leave your wife, or it’s over.

At first, it seemed the high-powered attorney wasn’t going to be bossed around by his mistress, but eventually, he relented and showed up on Dianne’s doorstep with a garbage bag full of his clothing.

Dianne was a woman who knew how to get what she wanted, and before she agreed to allow Alan back into her life, he had to stipulate to two things: Purchase her a new home and get her pregnant.

Over Before It Began

Although Alan hadn’t married her by the time their daughter Andrea Masters was born in July 1977, Dianne still believed she had gotten her man. She came to realize that she’d gotten more than she’d bargained for.

Dianne knew Alan had some shady dealings, but being with him on a daily basis exposed her to just how corrupt and criminal her boyfriend really was. Dianne had a front-row seat to Alan’s payoffs to dirty cops and judges, his shoulder-rubbing with organized crime, and his ownership in a Chicago brothel—the latter disgusting her more than any of Alan’s illegal activities.

Dianne and Alan Masters with their daughter

Dianne and Alan Masters with their daughter

By 1979, Dianne was completely disenchanted with Alan and, taking Andrea with her, left him to move in with her brother, Randall Turner, and his wife, Kathy. It was then that Dianne finally revealed to her brother the physical abuse she had endured and the fear she had of Alan.

Within days, Alan had tracked Dianne down and lured her home again with promises of divorcing his wife, Benita Masters, as well as a trip to the exclusive La Costa Spa in Carlsbad, California.

Alan kept his promise of divorcing his wife, and the day after it was final, he and Dianne wed in a civil ceremony at City Hall on March 25, 1980. It was not the large church wedding Dianne had envisioned; several times in the next couple of years, she would make the statement to various people: “The way I live and the way I dress, and I get married in a pair of blue jeans!”

The honeymoon was even more disastrous in Dianne’s eyes, as Alan had invited another couple along for their voyage on the Queen Elizabeth II.

For Dianne, it was not the forced divorce from a first wife, the untold scores of broken promises, or domestic violence that made her finally realize life with Alan was not going to be so great; no, for this young woman, it was a casual beginning that triggered the events of a very dramatic end.

Dianne Plans for a Divorce

Getting married for a second time didn’t make Alan give up his adulterous games. Dianne confronted Alan with his infidelity, and he, in turn, accused Dianne of the same. Round and round they went with the bitter arguments, screaming accusations, and fights that often turned physical. By the time they headed out on a much-needed vacation in Sarasota, Florida, in December 1981, Dianne had decided it was Alan’s last chance to prove he was willing to change to save their marriage, or she was going to divorce him.

It was really no surprise to anyone that Alan failed miserably at the test Dianne had laid before him. It began with his returning home early, claiming he had pressing business at the office, even though the courts were closed for the holidays.

Arriving home just days after the new year of 1982, Dianne began deciding how to best divorce Alan. She knew her husband would not go quietly, and Dianne did not intend to go penniless, so meticulous planning had to be done before she announced her intentions to Alan.

As Dianne went about the business of secretly planning a divorce, she carried on with her civic activities like being trustee of the Moraine Valley Community College board. It was through this position that Dianne met Jim Koscielniak.

A Jim Among the Ruins

In the fall of 1981, she and Jim began meeting for coffee. Their conversations had begun with a focus on education, but as time went on, they had started exchanging personal tidbits of information. Jim talked with Dianne about life as a divorced dad, and she, in turn, disclosed the marital discord between her and Alan, talking freely about their sexual incompatibility and his seeming disregard for their marriage vows.

When she made the decision in early 1982 to finally call it quits, Jim was undoubtedly a factor Dianne considered. As a matter of fact, before she left on vacation with her husband and daughter, she and Jim had become intimate following a faculty Christmas party. So, it wasn’t a leap to allow the relationship to become a full-blown affair after her mind was made up.

Dianne had become like a silly schoolgirl as her liaisons with Jim grew in frequency. She was well aware of her husband's many connections throughout the city and suburbs of Chicago, and she took precautions to keep the affair from being discovered, yet her giddiness would lead to foolish risk-taking.

In choosing to have an affair and planning to divorce her husband, Dianne Masters had taken a gamble. When she lost, the price would be her life.

Dianne Disappears

On the evening of March 18, 1982, Dianne attended a board meeting at the college. She didn’t see Jim that evening as they had agreed it would be best until her divorce was finalized that he not attend.

When the meeting adjourned, Dianne went out for drinks with other board members as was customary. As she said goodbye to the others in the parking lot at about 1:00 a.m. on the morning of March 19, no one knew it was the last time Dianne would ever be seen alive.

Dianne Masters

Dianne Masters

The next morning when the Masters’ housekeeper Donna arrived, she found Alan at the kitchen table with his daughter, which was unusual since he had usually departed for his office by the time she arrived. When she asked about Dianne, Alan told her his wife was missing and that he had been calling everyone he could think of trying to find her.

At 2:30 p.m. that afternoon, Alan phoned the Cook County Sheriff’s Department and reported his wife missing. A report was taken by the responding officer, and in such it was stated that Alan was anticipating his wife filing for divorce and that she had recently removed over $200,000 worth of jewelry from the residence.

Alan refused to publicize Dianne’s disappearance, much to the frustration of her brother and sister-in-law as well as many friends. They perceived this as a sign of Alan’s involvement while he insisted that it would be an embarrassment to Dianne, who, he said, was probably shacked up with a boyfriend somewhere—this despite his previous proclamations that Dianne would have never abandoned Andrea.

Randall, however, wasn’t going to remain quiet, and soon the story of the missing rich white lady was a major news story throughout most of Illinois. Everyone was keeping an eye out for her yellow-and-white Cadillac Coupe de Ville.

With his wife missing and the work of a couple of determined detectives who refused to be cronies on the attorney’s payroll, much of Alan’s dirty deeds began coming to light. And as the number of unscrupulous endeavors associated with Alan grew, so did the suspicion that he was responsible for his wife’s disappearance. The media all but outright said, “Alan Masters murdered his wife!”

But those headlines were coming. It might take a lot of shoe leather and door knocking to finally get the accusations in print, but yes, they were indeed coming.

The Busybody and the Boyfriend

For all of the meticulous planning, Alan had counted on a busybody being the first clue that his wife was the victim of murder and not a runaway wife.

Genevieve Capstaff, for whatever reason, had decided to see if anyone in the MVCC group was having an affair, so she had departed the meeting 40 minutes before everyone else and moved her station wagon to a dimly lit area of the parking lot to wait and watch. Dianne, being the last of the group to depart, became the subject of Capstaff’s private moving surveillance. When Capstaff last saw Dianne’s car, she was less than 100 yards from the Masters’ residence.

Realizing that Dianne wasn’t simply hiding out somewhere in fear, boyfriend Jim finally came forward and began talking about things Dianne had told him; such as the night, following one of their arguments that Alan had told Dianne she would be meeting with her parents, both by now deceased, very soon. According to Jim, that particular incident had shaken Dianne more than anything else Alan had said to her.

Once Jim became public knowledge, more and more of Dianne’s friends and family began coming forward with tales of Alan’s infidelity, the domestic disputes that often left Dianne with bruises, and more.

Alan had done a lot in his career as a lawyer, but nothing would earn him newspaper headlines quite like that of which was about to put him center stage.

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Buried Secrets

Tire tracks leading into the Chicago Sanitary and Shipping Canal became a concern for law enforcement; they dispatched divers to search the waterway.

From the discoveries made by the divers, it was apparent that the shipping canal had become a popular dumping ground for vehicles stolen or just claimed to be stolen. As a matter of fact, it would soon come to light that several cops were paid handsomely by crooks to dump cars in the canal for the purposes of insurance fraud.

The biggest find in the shipping canal, however, had been reported but not stolen. It was the yellow-and-white Cadillac so many had been searching for. As it was pulled from the murky waters, many believed they would finally know what had happened to Dianne Masters. They weren’t wrong.

On December 11, 1982, Dianne was no longer a missing person. Found in the trunk of the Cadillac, Dianne had been killed by two gunshot wounds to the head.

Justice for Dianne

Detectives felt certain Alan Masters was responsible for the murder of his wife, but they just didn’t have the evidence they needed to charge him. After all, they were dealing with a man skilled in criminal defense and knew his own charges would incite the lawyer to fight harder than he ever had for his clients.

But it didn’t mean they were just willing to give up. While the Chicago murder rates continued to rise and their workloads increased, they may not have been able to dedicate as much time to solving Dianne’s murders as they would have liked, but it didn’t mean they had forgotten her.

In the meantime, Alan had battled Dianne’s brother over her portion of the estate and custody of Andrea. Alan had married Janet Bowers, the nanny he had hired shortly after Dianne’s disappearance, in no doubt what was a move to keep his daughter at home.

One by one, however, witnesses began to come forward, the most damaging being Ted Nykaza, an alcoholic turned private detective who’d become a member of the Masters' payroll.

Nykaza told investigators about officer James Keating and Willow Springs police chief Michael “Mike” Corbitt, who had been dispatched by Alan to kill Dianne for several reasons, including ensuring Alan retained custody of his daughter and to keep her quiet about their criminal activities.

On June 13, 1988, more than six years after Alan reported his wife missing, Alan, Keating, and Corbit were arrested on charges of first-degree murder. Following trials that included a lot of finger-pointing and self-serving half-truths, all three men were found guilty. In August 1989, Keating and Corbitt were sentenced to 20 years, and, as the mastermind of his wife’s murder, Alan Masters was sentenced to 40 years in prison.

And in the End...

Jan Masters maintained custody of Andrea after her husband was sent to prison, but she and Randy Turner did finally reach an agreement that allowed him to keep in contact with his niece.

Andrea Masters followed in daddy’s footsteps and is now a practicing Chicago area attorney. Alan’s sons from his first marriage, Stephen Masters and Douglas Masters, are lawyers as well.

Mike Corbitt died at the age of 60 of lung cancer in July 2004.

And last, but certainly not least, Alan Masters went to meet his maker while still doing time in federal prison on October 9, 2000. Before his death, Alan finally admitted to being the mastermind in Dianne’s murder, which was outlined in a letter delivered to prosecutors.

Read More About Alan Masters

There have at least three books written about the fatal marriage of Alan and Diane Masters, but the best researched and written one I recommend is Blind Justice by Ray and Edie Gibson with contribution from Randall Turner, Dianne's brother.

Questions & Answers

Question: I heard that Dianne Masters was instrumental in establishing a shelter for battered women. If this is true, why is this not mentioned in this article?

Answer: I have never come across any information of the sort. A quick Google search returns an article written in 2015 (prior to this publication) that says Diane Masters started an organization/hotline for battered women from her kitchen prior to her death. The shelter came into existence after her death as a continuation of her organization.

© 2016 Kim Bryan


KHT on August 10, 2020:

Diane Scott I wondered how well you knew her? Well I am her sister in law and I knew her. I guess you are innocent RIGHT!

PLC on April 01, 2020:

I worked with Lt Jim Keating at the Cook County Sheriff's Police Department. He, like many other high ranking police officers from that police department...corrupt. There's a reason they call it Crook County.

Timothy on September 06, 2018:

Brian Dennehey was magnificent in this movie. It showed his true strengths and talent for this thriller. This is one of my favorite shows. My son did a paper on these murders in college and the things he was able to find out were very interesting as well as disturbing.

Yvette Williams on August 15, 2018:

I remember when i first saw the movie "Deadly Matrimony," Brian Dennehey was the cop i think who refused to back off from the husband....That movie was really all i knew of this case, but because of not knowing the entire, true story i cant wait to get my hands on the book!

DIANE SCOTT on December 25, 2017:

She wasn't as innocent as they portrayed her in the movie.

lettie baula on May 21, 2017:

The movie based on this story was really interesting DEADLY MATRIMONY. True stories are indeed more captivating than fiction. The twists and turns, the characters and their motivations, the various criminal activities that go on in big cities, i just can't imagine a fiction writer putting all these things together. Great story, great movie and now I aim to read BLIND JUSTICE.

Martin on January 25, 2017:

Sorry, I have no sympathy! A typical money hungry Polish tramp. Starving from Eastern Europe! She was having affairs from the time she crawled out of her mothers vagina! Her first husband, then second, it seems she had some serious screws loose herself. She knew what was going on. Uneducated, and starving for attention she jumped to the next adventure. Get real. Her brothers little memo is not going to make her into a Saint. Many people who knew her personally knew very well she was no independent woman! Had she been smart she would have left without trying to get EVIL MONEY to support her.

Suzie from Carson City on April 25, 2016:

Kim....This particular story actually screams out a real "moral." Selfish & greedy are dangerous. The person who thinks they're achieving all they want, whenever they choose, no matter HOW they get it......winds up being the biggest loser.

This is one book I intend to read.

Greg de la Cruz on April 25, 2016:

Wow, that's a really long take. She sounds like a mob wife

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