SAN LUIS OBISPO, Calif. -

Investigators are hard at work again today carefully digging at a second location on a Cal Poly hillside for any evidence that might lead them to what happened to Kristin Smart.

Investigators are methodically searching an area under the schools iconic "P" sign and combing through each piece of dirt.

"This is what they do, they are the best at this so that's what you're seeing is the systematic, methodical approach from beginning to end," says Aaron Nix, with the San Luis Obispo County Sheriff's Department.

FBI Investigators are searching for anything that might help explain what happened to Kristin Smart when she disappeared 20 years ago. The last place she was seen was on Cal Poly's Campus.

"We have moved from site one to site two," says Nix.

Aaron Nix says they are searching three areas of interest and just wrapped up with the first.

"We found things of interest I can't say what they are at this point this is one part of a very involved forensic process," he says.

A process investigators say they are committed to.

"To be done by the end of the week was the goal but we are committed to staying here as long as it takes as is the FBI." says Nix.

Investigators say this is just one of the things they are focusing on in the case and say there are looking at other leads.