DNA dominated closing arguments in the "cold case" murder trial of Darnell Griffin this morning.

Prosecutor Kevin Takata called DNA "the most powerful tool in solving crimes today" and stressed that Griffin's DNA was found inside victim Evelyn Luka after she strangled and left for dead on a freeway median September 6, 1999.

Defense attorney E. Edward Aquino told the jury, "DNA equals 'do not assume,' " and argued that Griffin and Luka had consensual sex two days before the crime.

Griffin wasn't charged in the case until 2007, after a DNA sample provided by him was matched to evidence collected from Luka eight years earlier.

Aquino assailed the quality of the police investigation in the case, noting that possible leads weren't followed and potential witnesses weren't interviewed.

Takata did not argue that point. "It was not a good investigation, we'll concede that," he said.

"Does that mean an innocent man sits before you today? No, it means a guilty man was free for eight years," Takata said.

The jury will begin deliberating Griffin's fate this afternoon.