Caine, then 17, said her brother's girlfriend called her to tell her Cook hadn't returned home. Cook and his girlfriend hadn't had a fight, and there was no reason to think he would run away, Caine said. The family called police and waited, hoping Cook would return.
"It was unimaginable," Caine said. "It was a lot of confusion. We couldn't even think he was dead. He had to have run off or something."
It would be more than four years before a man would come forward with crucial information for Atlanta police. And it was 2009 before remains found were positively identified as belonging to Cook.
“He’s been missing since the day he left his home in 1997," Detective Vincent Velazquez told Channel 2 Action News.
Cook's family never knew of the person who gave information in 2002, Caine said. But as the months and weeks passed, the horrific reality set in, she said.
"After five or six years, it's like, ‘OK, he's not coming back,'" Caine said.
Caine said the death of her mother when she was 10 years old and James was 13 had made the siblings very close. When their mother died, the two lived with their grandparents, Caine said. Losing her brother as a teenager came as a complete shock, and no one had an explanation for it.
The first major break in the case came early in 2002, when an informant told police he knew Cook had been killed, Velazquez said. Police have interviewed the informant several times, including after Cook's remains were found.
In January 2009, two people hunting near the Fulton County Airport-Charlie Brown Field called police after finding what they believed to be a skull. Investigators uncovered more remains at the site, including a class ring containing the name "James Cook," Velazquez said.
When her brother's Westlake High School ring was found, Caine said she knew for sure he was gone. She was asked to submit DNA samples to the medical examiner's office, which she did.
It would be more than a year before DNA testing confirmed that the remains were Cook's.
"We didn't know for so long," Caine said. "We weren't able to have a memorial for him until 2010."
Cook's son, now 14, never had the chance to know his father.
Atlanta police have a man in custody, Velazquez said Wednesday. Jermaine Carter, who also goes by the name Jermaine Thomas, was arrested in Texas and extradited to Atlanta. He has been charged with murder for allegedly killing Cook and is being held in the Atlanta jail.
But the case isn't wrapped up. Investigators are hoping to find the suspect's then-girlfriend, who they hope may have more information about the death. It's possible Carter's girlfriend in 1997 was present for the crime or arrived at the suspected crime scene shortly after.
“We’re not suspecting her of committing any crimes at this point, but we’re still digging," Velazquez said.
The details provided by the informant have been consistent with findings in the investigation, according to the police.
"The information and details he’s provided have helped us," Velazquez said. "It’s not the only evidence we have, but it’s helped us.”
Anyone with information about the case is asked to contact Crime Stoppers Atlanta at 404-577-8477.