Barbara Ramos does not know 19-year-old Berkeley High School graduate, Justin Johnson who has been arrested for her son's murder. Johnson is in custody in South Carolina for the 2006 stabbing death of Juan Carlos Ramos.

"We feel very grateful to the Berkeley police for all the work they did, but it's bittersweet," said Ramos. "Nothing can ever take the place of our son."

The Ramos' lawyer, Robert Cheasty, says witnesses did not initially come forward to identify the killer at the teen house party.

"We were, and still are, dealing with a lot of young people, whose maturity level was not really there yet," said Cheasty.

Pieces of information were gathered as teens had conversations about the death on MySpace and Facebook.

"Some we've spoken to, and some we haven't been able to speak to yet," said Cheasty. "Some have been more forthcoming than others, and the police have had the same problem."

Ultimately, witness cooperation did lead to Johnson being named the suspect, and ultimately arrested.