In high school, Tiffany was spirited and outgoing, and loved acting. At 19, she left her hometown of Ocala, Fla., for the University of Central Florida in Orlando. There she met Andrew Allred, whom her parents deemed a little bit odd.
"When he'd come to the house, you'd have to tell him to sit down, you know, otherwise he would stand over by the door," Tiffany's mom, Kim Barwick said.
Tiffany and Allred's friends didn't always understand his weird behavior, either.
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"He was just extremely rude to everyone. You know, called people names," said a friend, Charles Bateman. Even though the Barwicks and Allred's friends found Andrew's behavior to be a little off, they never believed him capable of criminal violence.
Friends say Allred was a shy and reclusive type, Tiffany's complete opposite. But Tony Barwick, Tiffany's father, never felt concerned. He never witnessed any fighting between the two, or noticed any aggressive behavior, he said.
"Anything she wanted or needed, he took care of her," said Barwick.
Friends, too, noticed that Allred was good to Tiffany -- in the beginning at least. Before long, however, the sweetness began to disappear. Allred lapsed into his typical cranky, bullying behavior, friends said.
After nine months, Tiffany decided she had had enough.
"Next Tuesday I am breaking up with my boyfriend," she wrote in an online journal. "He doesn't know. I am fed up with it." Tiffany had decided to wait until after Allred's upcoming 21st birthday party. Allred's best friend from childhood, Michael Ruschak, 22, was helping to throw the party. Tiffany didn't want to ruin it.
Her plan did not work out. Allred hacked into her journal and discovered her plan. He threw her out of his birthday party and began throwing her things over the fence, reported friends who were at the party. The scene got uglier, and Allred, who was drunk at the time, began spraying his friends with beer and tossing firecrackers and rocks at Tiffany and others.
Teen Dating Violence: 'Allred's Here'
Ruschak stood up to Allred.
"Michael just told him, you know, this isn't how you treat somebody you care about, this is not how you treat women," his mother, Janice Ruschak said.
Allred cut communication with Ruschak after the party, but he wanted Tiffany back, begging her forgiveness. Meanwhile, Allred began obsessing about Michael and Tiffany's friendship, becoming convinced the two were romantically involved. He harassed Tiffany with spiteful instant messages. He even changed all of her computer passwords and sent nasty e-mails to Tiffany's friends and family, making it look like they came from Tiffany.
On Sept. 24, 2007, Tiffany became so upset she called the sheriff's office. She told police she wanted to press charges against Allred, saying he was harassing and threatening her. She met with police that day, but Allred was never questioned or arrested.
That evening, Tiffany went to a cookout at a home where Ruschak was living with two friends. Allred had a plan of his own.
Ruschak's friends, Charles Bateman, 23, and Eric Roberts, 23, recounted the evening to "Primetime." Tiffany, Michael and friends were hanging out at the house when they heard a loud bang. It was Allred, ramming his truck into Tiffany's car.
Bateman said Michael wasn't concerned.
"Mike's in the kitchen and he's like, 'Allred's here,' he wasn't concerned or scared," said Bateman. "He was kind of -- it was like half a chuckle, you know, Allred's here."
Allred banged on the front door. Then he went around back. He had a .45-caliber handgun. The first shot shattered a sliding glass door. He saw Ruschak, and before Michael could even speak, he fired at him.
"Mike was about to say something and [Allred] pulled the gun and shot him and, right in the stomach," Roberts, a friend at the scene, said. Roberts said he tried to grab Allred from behind to stop him from shooting, but Allred shot him in the leg and got loose.
Ruschak would die from his wound.
Tiffany had locked herself in a bathroom. Allred broke down the door and shot her several times, killing her.
Allred is now on Florida's death row.
Teen Dating Violence: Warning Signs
Dating violence affects teens and young adults all over the country. Abusive relationships commonly follow identifiable patterns.
"If you have a daughter, for example, who cries a lot, if she's begging and pleading and apologizing for things she's never done -- that's an abusive relationship," said dating violence expert Jill Murray. "If throwing things out the window doesn't feel like loving behavior, if isolating you from your friends doesn't feel like loving behavior, then it's not."
Teens and young adults should know where to go when they feel they're in a potentially dangerous relationship.
Today, the Barwicks and the Ruschaks have been working tirelessly to help prevent others from brutal dating violence.
They've worked with the Florida Legislature to help create and pass the Barwick-Ruschak Act. This act places dating abuse on par with marital domestic abuse. It intends to save young adults who may be in situations similar to Tiffany's.
Both families believe these tragic events might have been prevented if an officer had spoken with Allred.
"If somebody had put their foot down to him," Murray said, "somebody with authority and said, 'You know what, kid, we're gonna have to haul you in if you keep on doing this,' or if they had taken him in for the night and really scared him, I think this could have been prevented."
CLICK HERE for warning signs of emotional and physical abuse and ways for teens to avoid abusive behavior in relationships.