On January 19, 2014, Donna Muller, 49, and her 22-year-old son, Richard, were discovered fatally shot inside their Philadelphia home. The investigation yielded insufficient evidence to identify a suspect. Despite the city offering a $20,000 reward for information leading to an arrest, the perpetrator remains unidentified

In 1971, a young couple vanished after leaving a Valentine’s Day dance, only to be discovered 13 days later tied to a tree in a secluded area of Orange County, North Carolina. The perpetrator repeatedly strangled the victims, letting them regain consciousness before repeating the brutal act. The case remains unsolved, with no official suspects named due to a lack of evidence.

In 2011, Agnes Dupont de Ligonnes and her four children were shot and killed in France. The father, Xavier Dupont de Ligonnes, became the prime suspect and disappeared. The bodies, discovered buried in the backyard, led to a manhunt, but Xavier’s whereabouts remain unknown. In 2015, a letter and photograph claiming he was alive reached a journalist, but its authenticity remains uncertain.

The Walkers and their two toddlers were murdered on December 19, 1959, in Osprey, Florida, with potential links to the suspects from the Clutter family murders that inspired Truman Capote’s “In Cold Blood.”

Perry Smith and Richard “Dick” Hickock, convicted and hanged for the Clutter murders, were the prime suspects. The case remained unsolved despite inconclusive DNA evidence from the 2013 exhumation of the bodies due to sample degradation.

In 1897, a Nashville neighbor discovered the Ade family’s house in flames. Initially thought to be an accident, the investigation later revealed a sinister plot. The family was likely forced into the parlor and attacked with heavy objects, with the youngest, Rosa, managing to escape briefly before being murdered. The fire was used as a cover-up. Unfortunately, heavy rains that night erased potential evidence, leaving the case enshrouded in mystery.

The Robison family, also known as the Good Hart murders, experienced a tragic mass killing. Richard Robison, his wife Shirley, and their four children, Ritchie, Gary, Randy, and Susan, were the victims. The upper-middle-class family from Lathrup Village, Michigan, had been vacationing at their Lake Michigan cottage near Good Hart.

The gruesome discovery was made when ladies playing bridge nearby noticed a foul smell emanating from the Robison’s cabin. Upon investigation, they found the entire family dead for over a month, beaten, shot, and amidst overturned furniture and broken glass. Despite having a few prime suspects, the lack of substantial evidence left the murders unresolved.

The Keddie Murders, an unsolved 1981 quadruple murder in Keddie, California, involved the brutal deaths of Sue Sharp, her son Johnny, his friend Dana, and daughter Tina in cabin 28. Tina was kidnapped and found dead three years later. The crime scene, discovered by Sue’s eldest daughter Sheila, revealed inconsistencies in the stories of the two younger sons and the friend.

Despite suspicions surrounding the Smartt family and a family friend, John “Bo” Boubede, the investigation was poorly handled. Many questions remain unanswered, and no further inquiries were made. Cabin 28 was demolished in 2004, leaving the case unsolved and the town in fear.

The unsolved murder of 21-year-old couple Connie Reynosa and Jesse Rodriguez in San Antonio lingers as a mystery. On the night of February 10, 2012, after leaving a sports bar with a friend, the trio became victims of a sudden shooting, resulting in the deaths of Connie and Jesse and injuring their friend. Despite the incident, no suspects have been identified, and the case remains open.

In 1922, the bodies of Reverend Edward Wheeler Hall and Eleanor Mills were found in a New Brunswick apple orchard. Mills had been repeatedly shot with her throat slashed, while Hall had a gunshot wound to the head. Explicit love letters between them were discovered on top of their bodies, indicating a potential motive related to their affair.

However, the crime scene was mishandled by the police, and no autopsies were conducted. Despite family members being named as suspects and the identification of fingerprints belonging to Hall’s brother-in-law four years later, all suspects were acquitted of any charges. The murders of Hall and Mills remain unsolved.

On December 12, 1985, Mike Riemer, Diana Robertson, and their two-year-old daughter went to find a Christmas tree in Tacoma, Washington. Hours later, their daughter, Crystal, was found alone, mentioning her parents were in the trees. Two months later, their truck was found with Diana stabbed and a sock tied around her neck. Mike was missing.

The crime resembled an unsolved murder from four months earlier. Authorities suspected Mike due to his abusive history. He was considered a fugitive until 2011 when a skull fragment was found near the murder scene. The question of who committed the crime remains unanswered.

In 1983, Bernd Goericke and his fiancée Andrea Scherpf were found shot to death on a remote road in British Columbia during their vacation to Canada. The couple, seen hitchhiking with camping gear, had their possessions never recovered, except for a pair of bloody jeans at the crime scene.

Six years later, a tip led to the arrest of Andy Rose, who was convicted in 1991 based on his former girlfriend’s testimony. After an appeal and retrial in 1994, Rose was convicted again but was exonerated and released in 2001 when DNA on the bloody jeans did not match him. To date, nearly 30 years later, the real killer of Bernd Goericke and Andrea Scherpf remains unknown.

In Oregon, Illinois, on the evening of June 25, 1948, 17-year-old Mary Jane Reed and her date, 28-year-old Stanley Skridla, were last seen driving toward County Farm Road, a local lovers’ lane. The next morning, Stanley’s body was discovered on the roadside, shot multiple times, with his vehicle half a mile away. Mary Jane’s body was found four days later in a ditch, shot once in the head, with no signs of sexual assault.

A possible suspect was a married police officer allegedly having an affair with Mary Jane. Eyewitnesses reported seeing him tailing the couple on the night of the murders, but there was no evidence linking him to the crime. The case remained cold for decades until 2005 when Mary Jane’s body was exhumed. Shockingly, the skull in her casket did not belong to her but to an unidentified Asian man. Mary Jane’s actual skull has never been found, adding a bizarre twist to this unsolved mystery.

In 2000, the Miyazawa family—Mikio, Yasuko, and their two children—was discovered brutally murdered in their home, with the son strangled and the others stabbed to death. Intriguingly, the killer remained in the house for up to 11 hours after the crime, using the family’s computer, eating ice cream, before departing the next morning.

Despite the discovery of clothing, one murder weapon, and some fingerprints, no suspects have been identified. The case involved about 190,000 officers, with 40 still actively working on it. The reward for information leading to the killer’s identification increased to 10 million yen, up from the original 3 million yen in 2000.

In March 2014, Maoye Sun, his wife Mei Xie, and their two young sons were tragically murdered in their Cypress, Texas home, each shot four times in the head. Despite receiving tips, no suspects have been named, and the Chinese community in which they lived has not provided leads. Insufficient information has hindered progress, leaving the case unsolved.

On January 15, 1984, Bruce Bennett tragically lost his life when a killer assaulted and sexually assaulted his 26-year-old wife, Debra, and 7-year-old daughter, Melissa. The attack also left their 3-year-old daughter, Vanessa, with a crushed jaw, causing jagged bones to puncture her windpipe. Vanessa, though severely injured, was the sole survivor. Her grandmother, Constance Bennett, discovered the tragedy when the family failed to show up for work at their furniture store.

Despite an investigation involving over 500 people being questioned, no leads were uncovered to solve the case, leaving it shrouded in mystery.

On August 4, 1892, Andrew and Abby were discovered brutally murdered in their Fall River, Massachusetts home, both brutally attacked with a hatchet. Andrew suffered 11 blows to his face, while Abby received 19 to the back of her head, resulting in their immediate deaths.

Lizzie, Andrew’s daughter and Abby’s stepdaughter, immediately became the prime suspect due to known animosity between her and her stepmother. During the trial, suspicions intensified when Lizzie burned a dress, claiming it had paint on it, but prosecutors alleged it was bloodstained, suggesting an attempt to cover up the crime. Despite these suspicions, Lizzie was acquitted, and the case remains inconclusive. Lizzie passed away in 1927, and no other suspects were charged.

Barbara and Patricia Grimes, 13 and 15 years old, respectively, went missing in December 1956 after leaving their Chicago home for the movie theater. Their frozen and naked bodies were discovered on January 10, 1957, on a rural Chicago road. Despite interviewing several suspects at the time, no charges were filed.

In 2010, a retired police officer reignited interest in the case and reopened the investigation. A witness, previously too afraid to come forward, emerged, claiming to have been with the Grimes sisters the night they disappeared. However, no charges have been filed, and the case remains unresolved.

In 1963, Robert Domingos, an 18-year-old star football player at Lompoc High School, and his 17-year-old fiancée, Linda Edwards, were found murdered on a remote beach in Santa Barbara County. The couple, set to graduate, had gone to sunbathe but never returned home. Their bodies were discovered the next day, with Robert shot 11 times and Linda nine. It was believed that the killer approached them on the beach, forcing Linda to bind Robert’s hands before shooting them as they attempted to flee.

The crime scene shared eerie similarities with the Zodiac Killer’s attack on Bryan Calvin Hartnell and Cecelia Ann Shepard in 1969 at Lake Berryessa. This has led to speculation that Robert and Linda could have been the Zodiac Killer’s first victims.

On the evening of February 21, 1970, Sandra Garcia, 20, and her fiancé, John Franklin Hood, left for East Beach near Santa Barbara with a blanket and food. The couple never returned, and their bodies were discovered the next morning on the beach. John had been stabbed 11 times, and Sandra was brutally mutilated.

The murder weapon, a bone-headed fish knife, was found buried in the sand beneath their bodies. The motive for the crime remained unclear, as nothing was stolen, and Sandra was not sexually assaulted. Speculation has arisen that the murders of John Franklin Hood and Sandra Garcia might be connected to the Zodiac Killer due to the similarities in the modus operandi.

On August 14, 2004, Jason Allen and Lindsay Cutshall were tragically murdered while camping on Fish Head Beach in Jenner, California. The crime, reminiscent of the Zodiac Killer’s brutality, involved the couple being shot in the head with a .45-caliber rifle while they slept. Discovered four days later, there were no signs of struggle, and none of their belongings were taken, ruling out theft or sexual assault.

Despite investigations and suspicions surrounding a drifter named Joseph Henry Burgess, who was killed in a 2009 police shootout, DNA testing did not link him to the crime scene. Numerous theories, including speculation about the Zodiac Killer’s involvement, have been proposed, but the case remains unsolved.

On September 7, 1988, a wealthy Long Island couple was brutally attacked in their home. Marty, their 17-year-old son, discovered his mother murdered and his father unconscious with a slashed throat. Despite Marty’s confession, he insisted it was coerced, pointing to Seymour’s business partner, Jerry Steuerman, as a likely suspect due to a financial dispute. Marty was released and cleared after appeals, but police never pursued Steuerman, leaving the Tankleff murders unsolved.

In November 1987, Jay Cook and Tanya Van Cuylenborg went camping in Washington State, possibly encountering their killer on a ferry. Tanya was found raped and shot on a rural road, and Jay’s beaten body was discovered under a bridge. Their van was found in downtown Bellingham with belongings scattered. Anonymous greeting cards sent to the victims’ families, claiming to be from the killer, were later traced to an unrelated mentally ill person. Over 25 years later, the murders remain unsolved.

On July 26, 1993, Harry and Megan Tooze were murdered at their South Wales farm. The killer shot Harry and, when Megan attempted to flee, she met the same fate. Their bodies were discovered wrapped in a carpet in the cowshed. Jonathan Jones, Cheryl Tooze’s fiancé, was the prime suspect due to a thumbprint found on a saucer inside their home.

Despite his conviction in 1995, Cheryl believed in his innocence and campaigned for his release. In 1996, the courts overturned the conviction, highlighting the lack of evidence linking Jonathan to the crime. The true killer of Harry and Megan Tooze remains unknown.

The 1977 double homicide of Maynard and Helen Fine in the Everett Hills area of Maryland remains unsolved. The couple was found shot to death at their home. Despite various theories over the years, authorities have been unable to gather enough evidence to make an arrest in the case.

On January 20, 2014, 28-year-old Chaunthina Mills and her boyfriend, 38-year-old Dwight Ray, were found dead in Dallas, TX. Chaunthina was discovered on the living room floor, while Dwight’s body was found on the porch, both with gunshot wounds to the upper body. The couple, who had a 15-month-old baby together named Urijah, was killed, and the case remains open due to insufficient evidence to identify a suspect.