Family of murdered Martha Post took the stand Monday on the first day of the trial for Marty Roe.
Roe is accused of killing Post on September 1st of 2011.
Prosecutors say Roe had become obsessed with Post, and believe that obsession lead to him murdering the Lexington dermatologist.
The sister of Post, Elizabeth Post and her daughter Caitlin Truitt both took the stand and said they knew that Roe had been harassing Martha Post for months.
They say they saw and heard messages Roe had left Post and say Post and become increasingly more concerned about her safety leading up to her death.
The defense says they believe Post's husband Bob Truitt is somehow responsible for the death of his wife.
They say Truitt had a large inheritance to gain from Post's death.
Family did say that Truitt did have a .38 caliber pistol, which forensic experts say was the same type of gun used to kill Post.
However family say Truitt bought the gun to protect his wife and himself, especially after Roe sent messages to Post talking about getting rid of Truitt, so they could be together.