Unfortunately, there are murders every day in this country.  Many of them are solved fairly quickly by law enforcement. Others take longer, much longer.  Still others are never solved.  In the day of DNA, it is still not a slam dunk to solve murders even in today's forensic science world.  Many murders are not solved because the body cannot be identified or the person is missing and presumed murdered. 

Murder is never an easy subject to discuss due to the violent and, yes, repugnant nature of the crime.  Motives of murder range from jealousy to anger to hushing a witness.  So, it is in the best interest of the murderer to hide his or her tracks as best as possible.  Sometimes murders are solved decades past the murder.  Some murders, such as those committed by serial killer, the Zodiac Killer (never identified or caught), are never solved.  One of the murders that was became nationwide headlines, in recent years, was the murder of six-year old JonBenet Ramsey.  Speculation was on the parents initially.  If you click on the link provided, you can read the latest update on that particular murder.  The list below are of some of the more noteworthy and, perhaps, not so noteworthy unsolved murders.
Mary Rogers, who was known as the "Cigar Girl," was murdered in July 28, 1841.  Her body was found in the Hudson River.  At the time, it was a national sensation.  What makes this even more noteworthy, this incident became the inspiration for author Edgar Allen Poe's "The Mystery of Mary Roget."

William Goebel, who was the Governor-elect of Kentucky, was murdered on January 30, 1900.  This was one day before he was to be sworn in as governor of the state of Kentucky.  He is still the only governor to be assassinated.

The Vampire Murder Case of Stockholm, Sweden, as it was called, an unnamed prostitute was found dead on May 4, 1932 with a crushed skull. Police stated someone had drank the victim's blood.

The Black Dahlia aka Elizabeth Short, is one of the most famous murder cases in U.S. history, occurred January 15, 1947 in Los Angeles.  The 22-year old was found greatly mutilated as her body had been cut in half.

Jamestown, Ohio. The Hernandez family has been missing since 1953. After the disappearance of the father and his two children, police officials searched the house finding Mr. Hernandez's wife stored in a cold room below their bedroom. To this day there is no record of the two children, or the father. J. Hernandez is suspected in the murder of his wife, E. Hernandez, and the disappearance of their two children.

 Marilyn Reese Sheppard, wife of Sam Sheppard, attacked and killed in her home in Bay Village, Ohio, United States, on 4 July 1954. Sam Sheppard was later convicted of killing his pregnant wife, but this was overturned in 1966, and he was acquitted in a new trial. He claimed his wife was killed by a bushy-haired man who also attacked him and knocked him unconscious twice. Their son slept through the night, just down the hall from the bedroom in which his mother was murdered. The trial of Sam Sheppard received extensive publicity and was called "carnival atmosphere" by the U.S. Supreme Court. The Sheppard case was a large part of the inspiration for the television series and later movie The Fugitive.

Bob Crane, an American actor best known for the TV series, Hogan's Heroes,  was found bludgeoned to death in Scottsdale, Arizona on June 29, 1978.  Crane supposedly called a friend of his the night before his death to tell him (John Henry Carpenter) that their friendship was over.  Police found blood smears in Carpenter's car that matched the blood type of Bob Crane.  However, no charges were filed at that time.  Carpenter was finally charged in 1994.  However, he was acquitted.  The case is now officially cold.

Karen A. Stiit, a 15 year old high school student was found stabbed over 60 times in the neck and chest on September 5, 1982. Her nude body was found in an alley behind the Honey Bee restaurant in Sunnyvale, California by a delivery driver making a delivery to the Woolworth Garden Center on Wolfe Road and El Camino Real. She was bound by her clothing, though no sexual assault was evident. Her murder remains unsolved.

Rashawn Brazell, disappeared after leaving his home in Bushwick, Brooklyn, New York, United States, on the morning of February 14, 2005. His dismembered body parts were later found in garbage bags. America's Most Wanted profiled the case three times, on  September 29 2005,  April 1 2006, and December 9 2006.