In highly populated areas south of San Diego, U.S. Border Patrol vehicles patrol dirt roads between 18-foot-high fences. Cameras monitor hard-to-reach valleys, and drivers must idle through Border Patrol checkpoints that sit 4,000 feet above sea level along Interstate 8 in the Jacumba Mountains.
The San Diego County sheriff's office is even enlisting beach lifeguards to help identify smugglers bearing drugs and illegal immigrants by boat from Mexico.
"In the 30 years I've been involved in law enforcement it has never been more secure," said Bejarano, now the chief of police in Chula Vista, a city 7 miles from the Mexican border.
The influx of fencing and manpower along California's border has made the region a difficult one to enter.
In 2000, federal officials caught more than 389,000 illegal immigrants in California. By 2010, that number had plummeted to just more than 100,000.
Through those years, as illegal immigrants have resorted to elaborate tunnels, fishing boats and ultralight planes to try to cross the border, many Southern Californians say the only constant has been lack of violence.
Lorena Nunez, a mother of two who's studying to become a teacher, lives so close to the border fence in Calexico that she recognizes the voice of a young man who usually helps illegal immigrants climb the fence.
Yet she said the abundance of Border Patrol agents patrolling her neighborhood actually works to her benefit, because illegal immigrants generally head north into larger cities.
"Do you see anyone nervous?" Nunez asked recently, pointing as neighborhood children walked home from school. "It's very protected here."
Some say the region is safe precisely because of the law enforcement buildup that has been assigned to the border.
"More cops equal less crime," said Mark Krikorian, executive director of the Center for Immigration Services. "It seems to be plausible, and it is precisely the increased federal presence at the border making those places safer."
Others along the border say the region was just as safe before the fence went up.
Raymond Loera remembers growing up in the 1960s in Imperial Valley -- a farming region about two hours east of San Diego -- and seeing illegal immigrants pass by his home.
Although his family was isolated, he said they never felt threatened.
"My mom, on a regular basis, would give them water or whatever food we may have had," said Loera, now the sheriff of the Imperial County sheriff's office. "I don't know that I ever heard of there being crime."
Burglaries have been increasing in Calexico this year, but Police Chief Jim Neujahr said illegal immigrants or drug traffickers are not to blame.
"The people we're catching are not illegal aliens, we're catching parolees and people like that," he said, referring to a wave of Californians being released from crowded prisons. "We have more problems from our local citizens than we do from people from Mexico."