Kay Wenal was married to real estate developer and millionaire Hal Wenal. They lived in Lawrenceville, Ga. Friends and family say they led a very glamorous life.

Kay's younger sister Pam Sleeper, pictured left, told "48 Hours," "Once you knew her, you loved her forever." 

Pam and Kay enjoyed going on trips together.

On the day of her murder Kay stayed home sick from work and investigators believe the assailant knew she was home alone. Kay's body was found in this position by her husband, Hal Wenal.

VIDEO: Inside the crime scene

Investigators believe Kay Wenal opened her front door and let the killer inside her home. There was no sign of forced entry.  

Blood drops in front of the stairs led investigators to theorize that Kay was immediately punched in the face when she opened the door. 

VIDEO: Inside the crime scene

Investigators believe the punch sent her glasses flying.  This crime scene photo shows where her glasses were found.

VIDEO: Inside the crime scene

Investigators believe Kay was chased through the hall and to the kitchen, where the assailant grabbed her and slashed her throat – twice. Investigators tell "48 Hours,"  "he decided to do what we call an insurance cut, a second cut … to make sure that she was going to die."

This bloody area is where Kay's body was found.

VIDEO: Inside the crime scene

No murder weapon has ever been recovered, but investigators say it was "an extremely sharp instrument."

Former FBI Agent Ned Timmons told "48 Hours," "Iit could've been a hunting or fishing knife … it did not cause any jagged lacerations."

The only physical evidence left at the scene were pieces of a mysterious latex glove.

The glove did not match ones used by first responders.

VIDEO: Inside the crime scene

Officials agree this murder was not tied to a robbery. Kay's wallet and credit cards were out in the open and expensive jewelry like the ones found in this drawer inside Kay's closet, could be easily found in the bedroom.

VIDEO: Inside the crime scene

One of the Wenal's neighbors told police that he saw a strange man in their cul-de-sac on the day of the murder and the day before. This sketch was compiled with the help of that neighbor and the Gwinnett County Police Department. The man has never been identified. Do you know who it is?

Can you identify the man in the sketch?

Anyone with information is asked to contact:

Gwinnett County Criminal Investigation Division Anonymous tip line: 1-770-513-5390

Crime Stoppers Atlanta: 1-404-577-TIPS [8477]

Hal Wenal hired his own team of private investigators to work on the case. He even offered a reward – that grew to $250,000 -- for anyone who came forward with information about Kay's murder.

Almost three months after Kay Wenal's murder, a shocking letter arrived at the offices of The Atlanta Journal-Constitution. The letter was filled with expletives and was made by pieces of cut out letters from magazines all glued onto a page. Investigators say no DNA could be found.

Hal Wenal died of a heart attack in 2010. His estate cut off the reward and his team of private investigators was fired. Former FBI Agent John Insogna tells "48 Hours," "there were things we wanted to do, other leads that we wanted to follow up on." Hal was buried next to his wife, Kay.

Kay Wenal's murder investigation has gone cold. Her younger sister, Pam Sleeper, is desperately clinging to hope. "If it was me Kay would not give up, and I'm not going to give up." 

Do you have any information? Please contact:

Gwinnett County Criminal Investigation Division Anonymous tip line: 1-770-513-5390

Crime Stoppers Atlanta: 1-404-577-TIPS [8477]

Solve this case: Who killed Kay Wenal?