It's the heartbreaking thought that lives with Narrandera woman Betsy Mahoney every single day. 

Twenty years have now passed since her brother David Beer was shot dead on his tractor as he slashed grass outside his property at Tallandoon, Victoria, on February 6, 1994.

An initial year-long investigation found nothing and, when it was reopened in April 2012 as a cold case, a $100,000 reward was offered for information leading to a conviction.

That reward still stands but Mrs Mahoney has heard little since.

Her battle for justice is ongoing and regular contact is kept with homicide detectives. 

She claims only two things will stop that - her death or a murder charge.

"They do tell me that murders are never closed until someone's charged," Mrs Mahoney said.

"I can't bear the thought (his case is) ... in a box, in the corner, gathering dust somewhere."

She said some days Mr Beer's death feels like just yesterday; on others that becomes an eternity.

The years may pass but Mrs Mahoney's love for her brother won't weary.

"The hurt's still there, it still hurts as much as it did the day I found out," she said, trying to hold back tears.

But there's one thing that hurts even more. 

"Somebody knows what happened, someone knows who did this," she said. 

"How can you live with yourself?

"Come and put themselves in our place, how would they feel if it was someone they loved and cared about?

"If you know something and aren't coming forward, you're just as big of a coward as the person who did this. 

"He didn't have a chance ... no chance to protect himself whatsoever."

Mrs Mahoney called Mr Beer, a farmer and property sales agent with Elders Albury at the time, on the day of his death.

"I tried to ring him and, ironically, he was on the tractor at the time," she said.

Her nephew Wayne answered the phone and Mrs Mahoney remembers saying: "tell him I love him and I'll see him Friday".

That night someone ended the life of a man she described as a "loveable larrikin, who'd give you the shirt off his back if it was the only one he had".

Husband Col broke the news to her the following day - the look on his face and the words uttered are forever etched in her mind. 

She had previously asked about staying with Mr Beer for a wedding later that week, to which he replied "sis, for you I'd get out of my own bed, but not for anyone else". 

Mrs Mahoney said she'd always wondered what how people coped with the fact someone hated another person so much they would kill them.

It was a concept she never thought she'd have to deal with.

"I just beg anyone who knows anything to please come forward and have some justice for him," she said.

"Some justice so that he can rest in peace and I can rest."

Murder puzzle pieces still missing, fight for justice ongoing

AFTER 20 years and numerous attempts to piece a murder puzzle together there are still no answers for the family of David Beer. 

The question - why? 

Why a 54-year-old son, brother, father and grandfather, was gunned down as he went about his business.

An article - published in The Daily Advertiser on February 9, 1994 - reveals the police investigation in following days.

"Police yesterday searched a river for the weapon used to murder of a man whose body was found slumped over his tractor on Monday near Albury," the first paragraph read. 

A passing motorist discovered Mr Beer's body outside his property on Lockharts Gap Road at Tallandoon about 8am on February 7. 

He was found with a single gunshot wound to his chest.

At the time the homicide squad said it appeared he had been dead for "some hours" and could have been shot on the Sunday night.

Police door-knocked the area and searched nearby farmland. 

Members of the police search and rescue squad also scoured the nearby Mitta Mitta River in the hope of finding the murder weapon. 

A river search was again carried out in the Murray River during March 2003, as the hunt for evidence continued.