BOULEVARD, Calif. -- Nearly 150 people searched areas around Boulevard on Saturday, hoping to find evidence related to an Orange County murder case.

According to the Orange County Sheriff's Department, Christopher Smith was killed by his former business partner, Edward Shin. Investigators said Shin confessed to the killing but never said where he put Smith's body.

Now, that mystery may soon be solved. On Saturday, members of the Orange County Sheriff's Department search and rescue team searched the area around Boulevard some 45 miles east of San Diego.

The search focused on an area near the Mexican border and east of Tecate.

"We're out here today just searching for evidence of the crime," said Orange County Sheriff's Lt. Chris Collier.

It is unknown if Shin told investigators the location of Smith's body. Investigators would not say what information that led them to the Boulevard area.

The San Diego County Sheriff's Department search and rescue team and agents with U.S. Immigrations and Customs Enforcement and the U.S. Border Patrol assisted in the search, which wrapped up at about 4 p.m.

Searchers found some items that might be evidence in the case, Collier told U-T San Diego. Collier declined to identify what those items were and said he did not know if human remains were found.

Prosecutors and the Orange County Sheriff's Department believe Shin killed Smith purely for financial gain.

"Mr. Smith wanted to separate from the company, but in order to do that, Mr. Shin had to pay him $1 million," said Orange County Sheriff's Lt. Jim Amormino. "Instead of paying him $1 million, he killed him."

Shin and Smith founded an advertising company called 800xchange.

Prosecutors say after Shin killed Smith in their San Juan Capistrano office, Shin cleaned and repainted it several times. They say they were still able to collect trace evidence of Smith's blood from the office.

Authorities believe Shin also engaged in an elaborate scheme to convince Smith's family that Smith was still alive by sending them emails pretending to be Smith, who was supposedly traveling around the world.

Shin was arrested last August in connection with Smith's death. Shin's former personal assistant and driver, Kenny Kraft, is also under arrest as an accessory to Smith's murder.