'If You're Reading This Letter, I'm Dead': Murdered Woman Helps Police Track Down Killer

When Griselda Cassamajor locked eyes with Drinel Joseph from across the dance floor, it seemed like love at first sight. Tragically, the romance would end in bloodshed and violence.

It was August 2006 when Cassamajor, 26, met Joseph, 27, at an Orlando nightclub. Cassamajor had been partying with friends when Joseph came over to woo her.

" [Cassamajor was] a beautiful woman ... Very outgoing, full of energy ... any man that saw Griselda would want to approach and talk to her," friends told "Killer Relationship With Faith Jenkins," streaming on Oxygen.

Cassamajor was quickly smitten with Joseph. Cassamajor, who had grown up in the Dominican Republic and moved to Florida, bonded with him over their shared Haitian descent. He made an effort to get to know her family and was generous with her.

"He was this tall, fit guy ... She thought he was such a  charming guy. He dressed nice, he smelled good, he was so cool," her cousin Daphney Parson recalled.

One potential snag in the relationship was the distance. Cassamajor, who dreamed of being a chiropractor and owning her own business, lived in Orlando and worked for a family clinic. Joseph, who had two young daughters, lived four hours away in Homestead. Still he regularly made the drive to see her and even got a job at a high-end steakhouse in Orlando so he could be closer to her.

Then, six months into the relationship, Cassmajor discovered she was pregnant. She was excited to have the baby, but the pregnancy ended in a miscarriage. And Joseph wasn't supportive of her during the difficult time.

"Joseph didn't show up [to the hospital]. She didn't expect him to react that way ... it was a gut punch for her," Parson said. " ... It was just really shocking how he acted to her when she lost the baby."

Joseph grew more distant, and the relationship faltered. Things took a turn for the worse when Cassamajor discovered he was still married. She ended the romance entirely.

After the breakup, Joseph's behavior became erratic. Suddenly, he started calling her all the time and showing up at her home, begging her to take him back. But Cassamajor insisted to family members that she had it under control.

Griselda Cassamajor

"She made it seem like she had a handle on it so as not to worry friends and family," Parson explained.

Eventually, Cassamajor started dating a local barber that friends and family described as "caring and sweet." Cassamajor seemed happier than ever with the new romance and a thriving career. 

"That's when she started being herself again," friend Fredy Carlos told producers.

On the morning of July 2, 2007, Cassamajor had car trouble, so Parson took her to work. She also accompanied Cassamajor for lunch along with Daniel Rivera, 20, the new massage therapist at the clinic. When Parson left, Cassamajor reminded her she had to pick her up. It was the last time Parson saw her alive.

Later that day, Cassamajor's aunt, who also worked part-time at the business, arrived at the clinic. She saw Rivera was hunched over his computer, seemingly asleep. She tried to wake him up but he didn't move. After seeing blood, she called authorities.

When investigators arrived at the scene, they found Rivera dead. Cassamajor had been shot twice in the head and was just clinging to life inside the clinic.  She was rushed to the hospital, where she was pronounced dead.

Little evidence was found at the scene, although Rivera's fiancé had spoken to him at 5:21 p.m. that day. Policed arrived at 6, meaning the killer had a narrow time frame.

Rivera's loved ones described him as a happy, charismatic person with no enemies. It didn't seem like he was the target. Was it Cassamajor? Evidence at the crime scene indicated Rivera had been shot first, before the killer chased Cassamajor down.

After reviewing the office's admission sheet, they noticed one woman had entered during the tight time frame. When they tracked her down, she said she had came in around 5:45 but thought Rivera was asleep. When she couldn't get his attention, she left.

“She didn't see Griselda’s body or anything in the parking lot," Robin Wilkinson, former assistant state attorney and head of the Homicide Unit, told producers.

Cassamajor's mother then found something chilling while going through her bedroom. In the dressers was a handwritten note from Cassamajor herself.

"It basically said if you're reading this letter I'm dead and Drinel Joseph did it," explained Wilkinson. "It appeared Griselda was developing a certain fear factor around Drinel and was attempting to distance herself from Drinel."

Friends also told investigators Joseph had been physically violent with Cassamajor, which raised more red flags.

Joseph was brought in for questioning, where he claimed to have an alibi. He said on July 2, 2007 he had gone into work at 8:30 but had gotten into a fight with the manager and left at 9:30. He then went to a mechanic shop to check on a truck, before arriving to his home around 4 p.m. But when police questioned the mechanic, they learned his alibi was inconsistent: The mechanic said he had actually left his place around 11, 11:30 a.m.

His cell phone records were examined, and showed he had indeed been in Orlando and by the clinic around the time of the murders. Investigators also discovered he had called a friend of Cassamajor's around that time to confirm she was at work there.

Prosecutors believed he had been furious with Cassamajor for moving on to a new relationship. He had entered the clinic when he knew she was there and shot Rivera, who was playing Solitaire on his computer at the time. He then chased Cassamajor down as she tried to flee and shot her twice in the head before immediately driving back to his home in Homestead.

Drinel Joseph was arrested on July 27, 2007 for murdering Rivera and Cassamajor. He stood trial in May 2008, where he didn't say a word in his defense. He was convicted and sentenced to life in prison without parole.

For more on this show and others like it, watch  "Killer Relationship With Faith Jenkins," streaming on Oxygen here.