Often, a bond exists between brother and sister that cannot be broken, despite - or perhaps because of - how many shared tragedies they may have endured.

For Kobi Walden and Kala Klein, that bond - always strong throughout their childhood - was irrevocably sealed when their father tragically died by suicide when Kala was only 13 years old.

Big brother Kobi, 19 at the time, became what Kala would later remember as "the co-keeper of my childhood."

As they grew further into adulthood, the siblings would share a unique, unshakeable bond that was only additionally cemented with the birth of Kala's four daughters. Kobi's young nieces adored their kindhearted, handsome, fun-loving, athletic uncle, and he would have gladly laid down his life for any one of them.

Sadly, that life was brutally cut short by a stranger as Kobi was returning to the place he should have felt most safe and secure - his home.

With his infectious smile and boundless energy, anyone attending an Indianapolis Race City Rebels Roller Derby match couldn’t help but be dazzled by the skills of #47.

A rising star athlete in the sport of amateur roller derby, Kobi was a beloved teammate and an integral part of the line-up.

Described by a close friend and fellow Rebel as a "unifier", a group of his teammates got matching commemorative tattoos in his honor after his murder. But it wasn't simply his athletic talents that set him apart; Kobi was said to be uplifting of everyone around him, and the type of person who made roller derby - and everything else - incredibly fun.

Always smiling and with what best friend Diana describes as "the best laugh on the planet," Kobi effortlessly drew people into his orbit and kept them close.

The people that lived deepest in his heart, however, were his four adorable nieces, the daughters of his sister Kala. In almost every available picture of Kobi, he is shown hugging and cuddling one or more of his nieces; with a brilliant, delighted smile plastered across his face and love shining from his eyes.

How do you explain to four little girls under the age of 10 that their favorite person - their incomparable Uncle Kobi - has been senselessly ripped from their lives, and that no one has yet been made to answer for taking his life?

The evening of May 1, 2017, was a typical Sunday.

Kobi had attended a Rebels practice session, where he’d had a tough but thoroughly satisfying workout. After leaving the rink, he’d stopped at a Kroger’s grocery store before returning to his Indianapolis apartment shortly after 10:00 pm.

Happy but exhausted from his physical efforts, he remained in the Southport Crossing Apartment complex’s parking lot in his vehicle for about 20 minutes, posting to Facebook about what a great practice he’d just had and how tired and sore his legs were.

After he left his car carrying a gym bag and his groceries, it was assumed that he was confronted by a gunman - perhaps the target of a robbery, police later theorize. This was further supported when it was discovered that Kobi’s father’s wedding ring, which he always wore, was missing, along with his cell phone and wallet.

Apparently, Kobi tried to run from his assailant but was fatally shot in his attempt to escape. His sister would later confirm that the bag of groceries and gym duffel were found neatly placed on the ground rather than scattered about, indicating that perhaps her brother had tried to reason with his attacker before attempting to flee.

At 10:03 pm, residents of the apartment complex reported hearing gunshots, which they at first assumed to be fireworks. They called 9-1-1 and authorities responded, but police were unable to locate any gunshot victim.

The following morning, a gruesome discovery was made.

At 11:45 am, a group of teenagers on a fishing trip stumbled across the body of a young man hidden in the woods along a creek behind an apartment complex near Highway 31 and Southport Road. The remains were identified as Kobi Walden, and authorities reported that he had been shot multiple times and was found lying face down near the creek. The victim was not easily visible, which was why officers responding to the ‘shots fired’ call the previous night were not able to spot him.

Upon the discovery of the Kobi, police also recovered the groceries and a gym bag in the parking lot of the apartment. Kobi's gym bag appeared undisturbed, but other personal items were missing - including the gold wedding ring with five small diamonds that he never took off.

Meanwhile that same day, Kala Klein received a disturbing call from Kobi’s employer letting her know that Kobi had not shown up for work that day, nor had he called in. Kobi, a retail store manager, was a reliable employee who had never before been a “no call/no show”; this was completely out of character for him.

By the following day, Kala would be called upon to perform the devastating task of identifying her beloved brother’s remains. Based on the robbery theory, police canvassed the apartment complex and immediate neighborhood, attempting to discover whether any suspicious activity had been observed. A witness eventually came forward, stating they had seen a man "lingering" about the apartment complex. This witness also confirmed that they saw Kobi sitting in his car on the night of the murder, but did not observe the shooting that resulted in Kobi's death.

During the investigation, authorities learned that Kala’s admiration of her brother’s character did not seem to be exaggerated - friends, teammates, colleagues, and acquaintances alike universally remembered Kobi the same way. He was well-liked, caused no trouble, and had a smile and a kind word for everyone.

The idea of the gentle, somewhat goofy, self-proclaimed “Star Wars fanatic” having any involvement with drugs or gang-related activity was frankly ludicrous, and any theories pointing to that were quickly ruled out. Authorities learned that Kobi had recently suffered a difficult breakup of an 8-year relationship, but when they explored that further, they found nothing to link the separation to Kobi's murder.

Nor did the fact that Kobi identified as gay seem to have any relevance to the crime. Despite receiving several tips and pursuing at least two persons of interest (one of whom knew Kobi), police were unable to develop any solid suspects in the young man’s murder.

Then, a mere month after the fatal shooting of Kobi Walden, another victim was killed by gun violence at the same apartment complex where Kobi had resided. Army veteran Erin Mills was gunned down around the corner from where Kobi's body had been discovered the prior month, while she was unloading her car after returning from a trip. Her fiancé was also found inside the apartment with at least one gunshot wound. Again, robbery was suspected as the motive in this shooting.

Police immediately began to attempt to link the two cases, but a week after the murder, authorities confirmed that the weapon used in the Mills killing was not the same as the one used to kill Kobi. Ultimately, no connection between the two shootings could be found.

Where the case stands today.

In 2018 - a little over a year after the murder - Kala received a terrifying midnight phone call about her brother’s murder, indicating that someone close to Kobi had threatened to kill him. The informant claimed that this person had asked someone for information about finding a gun and for possible assistance in killing Kobi. Although Kala immediately reported this tip to law enforcement, it ultimately produced no results.

In August of 2019, friends and family raised over $1,000.00 to have a huge billboard placed on U.S. 31 near I-465, just off Thompson Road, seeking information about the murder. The billboard reads “Who killed Kobi Lee Walden?"

They hope that by putting it up close to where Kobi was killed, it might prompt someone to remember something about the night of the murder and possibly come forward.

Kobi Lee Walden was only 31 years old when his life was brutally ripped away for what seems to have been no reason at all, leaving his family and friends - particularly his sister Kala - shattered with a grief that can never be assuaged. But perhaps the greatest collateral damage resulting from this heinous, cowardly crime was the impact on the littlest victims.

Kobi’s four young nieces continue to keenly feel the loss of their beloved uncle as they attempt to navigate a world that will never be the same as it was before that fateful spring night in 2017, when their familiar, joyful world was irrevocably altered by a cruel stranger. In a post dated March 11, 2020 for her “Letters to Kobi” blog, Kala admits to being haunted by what could have been - would her brother have settled upon a career that fulfilled him? Would he have fallen in love, planned a wedding and become a husband, and perhaps even a father by now? We will never know, and meanwhile, justice continues to elude this family that has already endured such unbearable suffering.