Part one of a two part series. Read part two here.

James "Whitey" Bulger's trial last summer described in detail the murders of 19 people in the 1960s, '70s and '80s.  But during those years, there were other unsolved murders that today are considered cold cases. Could there be a link between Bulger's criminal operation and the fate of a Boston bar owner who seemed far removed from the area’s criminal underground? WGBH News senior investigative reporter Phillip Martin has been looking into the disappearance of Owen Flynn.

On a frigid December day, lawyer Dan McDevitt is reminiscing on the Granite Avenue drawbridge between Boston and Milton. Beneath him, brown algae drifts on the Neponset River. Back in the 1970's, McDevitt fished from this spot.  

"Eight to 12 years old, I’d fish off that bridge. This place is a hotbed for striped bass all spring and into the summer," he said. 

Great for fishing, but McDevitt said this spot is less than idyllic for those contemplating ending their life.

"If someone wants to commit suicide, they’ll find a way. But there’s not enough height here even at dead low tide to effectively kill yourself. If you dove in head first at low tide, you’d probably just get a lot of bumps and bruises," he said.

That’s why some law enforcement officials are not convinced that a West End bartender named Owen Flynn took his own life by jumping from this bridge in 1972. It’s a case filled in mystery, especially with the backdrop of organized crime at the time.

Today, McDevitt works in an office that overlooks the same bridge.

"It’s really Dorchester’s access to the highway, and nothing's changed here since '72," he said.

What has changed since 1972 is renewed interest in Owen Flynn's death. Flynn's daughter, Ann Flynn Dickinson is determined to find out what happened to her father. Flynn Dickinson was a little girl when her dad left for work on December 7 to work in a new bar, Downey and Judge, where he was a silent partner, according to Flynn Dickinson. 

"He would go into the bar and tend bar at 2 in the afternoon and he wouldn’t come home until 1 or 2 in the morning," she said. "So it wasn’t not normal for us to see him in the morning. But my mother’s behavior made me think that something was just not right. I had a little brother who was two at the time and I remember tying his walking shoes and listening to her on the phone and saying 'he didn’t come home.' And that’s when I knew something was wrong."

Flynn Dickinson said she feels that police didn't care what happened to her father.

"As I got older, good friends in law enforcement would tell me, 'I think you need to look into this further, I think there’s something more to this,'" she said. "And when we looked at the death certificate -- when I got a copy of it -- sure enough it was not checked off as homicide or suicide. It was 'unknown.'"

The mystery of Owen Flynn’s death occurred during the heyday of organized crime in Boston. James "Whitey" Bulger was a rising force in the Winter Hill Gang, and in 1972 was involved in a bloody war with the Mullen Gang for control of bookmaking and other activities centered in the city's numerous speakeasies and bars.

MBTA Police Lt. Cmdr. William Fleming has been looking into Owen Flynn's disappearance on his own time. He said it may not be an isolated cold case.

"I’m sure that the harbor has several bodies," Fleming said. "Back in those days if you wanted to get rid of your car, you just drove it right into the Harbor. And I’m sure that several people have disappeared in the harbor and there’s never been an explanation of what happened to them."

This summer, several families finally got answers to what happened to their loved ones during Bulger's trial. Day after day, witnesses recounted the horrific nature of murders that took place between 1960 and 1990.

During breaks in the trial, several families, including the Flynns, approached law enforcement to ask if Bulger had a hand in their loved ones disappearances, deaths or murders. 

For 20 years, Massachusetts State Police detective Lt. Steve Johnson helped lead the search for Bulger and gathered evidence against him. Johnson also led the state team that dug up the remains of three of Bulger's and Stephen Flemmi’s victims. 

"We’ve had maybe a half dozen or so families on various homicides come to us and say to us that possibly their loved one could have met their demise at the hands of Mr. Bulger," Johnson said. "All of which is quite possible."

It was on the Neponset River where Owen Flynn's body was believed to have been carried by the current into the harbor.  

It could all just be a coincidence, and Owen Flynn's death unrelated to anything sinister. But his daughter doesn't know why he would have taken his own life. He had just purchased a new car and a new home.

"It was the white picket fence and the dream was coming true for us as a family," she said. 

But when Flynn didn't return home after work in December 1972, his children were bundled into a car with an aunt to spend time away from the house while adults searched for him. It was en route to her aunt’s home that Ann Flynn Dickinson made an auspicious discovery.

"And we were headed toward Gallivan Boulevard and on the Granite Avenue bridge was a car that looked just like my father’s, and I said to my aunt, 'That’s my father’s car,' and she said, 'What’s the license plate number?' And I used to recite it all the time. I knew it. And when we got over to the car, God, there was nobody in it. The car was locked. The keys were up on the dashboard. There was no note or anything."

The car was never impounded, searched for evidence or dusted for fingerprints, Flynn Dickinson said. It was towed to the family’s home in Braintree. Today, police describe the investigation at that time as just a “casual search” for the 42-year-old bartender and Irish immigrant. 

What happened to Owen Flynn? And could Bulger have played a role?  

Detective Lt. Steve Johnson of the Massachusetts State Police:

Johnson: It’s a possibility that's something Mr. Bulger was involved in. It’s within the realm of possibility.  

Reporter: What would make it possible?

Johnson: The location. Where the deceased car was found. The time period. It was a pretty active time for murders by organized crime figures during that juncture.

In late January of 1973 --  weeks after Owen Flynn’s car was found on the Granite Avenue bridge -- his badly decomposed body washed up miles away on Carson Beach in South Boston. And his death, some feel, either came about by a need to end it all through suicide or a murder, still unexplained.