ATLANTA -- Atlanta police said they believe John Platt was killed by another man over a $3 debt. A homicide detective told Channel 2’s Mark Winne it took her more than a year to get the witnesses she needed to break the case, but now she believes she has. An arrest was made in the case this week.

The detective on the case said David Blake’s name surfaced the first day she was on the case in June 2007. But it took her a year and a month to get evidence to charge him.

VIDEO: Suspect Named In Killing Over $3 Debt

“I had faith that sooner or later this will come to an end, but it took so long that I began to start to wonder,” said Dorothy Barber, the victim's sister.

“They killed my brother. That hurt me. Some nights, I cry,” said Larry Platt, the victim's brother.

Atlanta Police homicide Det. Nicole Redlinger said she believes 56-year-old John Platt was beaten and body slammed over a $3 drug debt. “The victim in this case was essentially defenseless,” said Redlinger.

Officials charged 24-year-old David Blake with Platt’s murder this week.

“The big break in this case is that after a year, I finally had witnesses that would cooperate and come forward in this case, which was a real big deal because the suspect in this case had created a lot of fear in the community,” said Redlinger.

By phone, a public defender’s office lawyer said he anticipates Blake will plead not guilty in the murder case. He said Blake already pleaded not guilty to a pending aggravated assault charge, for which he was already in jail.

“At the hospital, my brother passed on and they gave me the money in his pocket and I knew he could’ve paid him $3 and that boy just took hi life for nothing,” said Barber.