High school sweethearts Lanny Horwitz and Donna Carnevale, first and second from left, met in Buffalo, N,Y. Lanny's brother, Barry, far right, recalls many joyful memories in the years that followed, like this one at a costume party.
In this photo, Lanny, 11, helps straighten his father's tie. Lanny's brother, Barry, left, told "48 Hours" that Lanny had his eyes set on success at a young age. By age 16, Lanny was selling real estate for his father, a successful Buffalo developer.
Donna also came from a well- known family. Donna's father, Dan Carnevale, a Buffalo baseball hall of famer was the only man to ever play for, manage, and serve as general manager of the Buffalo Bisons.
The family moved to Boca Raton, Fla., in 1977. In 1990, they move to the gated community of Admiral's Cove in Jupiter, Fla. In this photo, Lanny oversees construction in the home he would be murdered in years later.
In the last few years of his brother's life, Barry Horwitz says Lanny was spending a lot of time with this woman, his business partner, Francine Tice. When asked if he sensed they were in love, Barry told "48 Hours" "They had just met, but they were holding hands. You know, kid stuff." Barry hadn't seen his brother looking so happy in 40 years.
Barry didn't know that Lanny had decided to give his relationship with Donna one last shot. By April 2011, Donna and Lanny had moved back in together - still divorced - along with their grown son Radley, a single dad.
The reunited family was short lived. On Sept. 30, 2011, Radley awoke to the sound of gunfire and his mother screaming. When he came downstairs, he discovered his father lying on the bathroom floor. He had been shot nine times.
Detective Frank told "48 Hours" that Donna Horwitz refused to answer any questions. In this photo taken that morning, she is barely visible, sitting in the passenger seat of Radley's car. Her hand is covering her face.
CSI Investigator Tracie McClendon processed the scene. Here, she takes "48 Hours"' Peter Van Sant through the crime scene, indicating a bullet hole in a towel that was hanging on the shower door. She says this shows that Lanny was first shot while in the shower.
McClendon points to where a phone hung on the wall. Lanny Horwitz was found with the receiver by his head, and the cord pinned between his arms. McClendon believes Lanny was trying to call for help. When investigators checked phone records, they found that Lanny was unable to complete any calls.
Investigators examined the Horwitz family's personal belongings. They discovered an arsenal of weapons: In addition to two revolvers used to murder Lanny, they found 24 other weapons ranging from handguns to assault rifles.
Prosecutors began to build the case against Donna, alleging that jealousy over Francine Tice was motive for murder. Tice adamantly denies that her relationship with Lanny was anything more than business partners and friends.
Prosecutors say communication between Francine and Lanny was constant, like this text message showing that that the night before the murder, Francine had planned to pick Lanny up at 8 a.m. for a business trip. The two never got to go. Lanny died an hour earlier.
On Jan. 11, 2013, Donna Horwitz's murder trial began. In a shocking twist defense attorney, Grey Tesh, shown here, points the finger at Radley. Referring to Lanny's life insurance policy, Tesh claims that Radley had "had half a million reasons to kill him."
Years earlier, Radley, a one-time licensed gun dealer, spent five months in prison for selling a handgun to a felon. Now a convicted felon himself, Radley had trouble finding work. Tesh was convinced that Radley was hard up enough for money to kill his father.
Tesh told the court it was possible that Radley had hired a hitman to do the job. To support this theory, Tesh pointed to unidentified DNA found under this smear of Lanny's blood on a gate at the home, possibly belonging to the real killer. Prosecutors argued that the DNA could have been left on the gate days or even weeks before the crime occurred.
Evidence supported various parts of Radley's testimony, including this orange earplug that was recovered at the home. Radley explained that as a light sleeper, he always slept with earplugs. When he heard gunfire, he removed them and stepped into a nightmare -- his father lying on the floor taking his last breaths.
CBS News obtained a layout of the home and enhanced the image to more clearly show the positioning of the rooms in relation to one another.
The bathroom where Lanny's body was found is on the right side of the master bedroom. Radley's room is at the bottom left of the floor plan. Radley walked through the living room and looked into the bathroom far enough to see his dad lying on the floor surrounded by blood.