Some people from other countries want to come to the United States to kill us. Some want to freeload off us or sell us illegal things. Most just want to work here. So what should be done about all that?
It's the Border Patrol's responsibility to secure the U.S. border from illegal immigrants, but the border is long, and Border Patrol agents can't be everywhere.
"The Border Patrol agents are overworked, undermanned, unappreciated," Crooks said. "I'm that added eyes and ears that the Border Patrol don't have."
Crooks thinks more needs to be done. "These borders have to be secured. We're at war."
Violence is an ongoing and escalating problem at the U.S.-Mexico border, resulting in more than 1,000 deaths so far this year, according to federal officials. The State Department recently issued a travel warning urging caution for Americans traveling to Mexico and Wednesday President Obama said he would consider deploying National Guard troops to the area to deal with the violence.
The president said while he didn't want to militarize the border, "I think it's unacceptable if you've got drug gangs crossing our borders and killing U.S. citizens."
Congress recently decided that the best way to protect America was to build a wall. So now taxpayers are paying for a barrier that later this year will extend 670 miles across our southern border. The Congressional Budget Office estimates the cost at nearly $2 billion and an additional $260 million per year just to maintain the fence.
Duncan Hunter, a former presidential candidate and retired California congressman, pushed for the fence his entire career and will gladly take credit for its creation.
"The fence succeeded because I wrote the language that mandated it," he said. " I added money each year in the drug interdiction budget to build that fence."
But while the fence is hundreds of miles long, the border is thousands of miles long, so most of the border will remain unfenced. And even where there is a fence, illegal immigrants determined to get in can get around it.
San Diego Border Patrol Chief Michael Fisher told "20/20," "They will try to come up over the fence. They will try to come underneath the fence. They'll try to swim around."
They often bring ladders, too. "20/20" went to San Diego to take a look and found dozens of abandoned ladders lying right next to the fence. We also found a series of holes that had been cut into the fence and subsequently repaired. Every few feet, one after the next, these repaired holes dot the brand new fence that Congress is building. It doesn't matter how high a fence is if you can just cut holes at the bottom.
There's also no evidence that the fence has reduced the number of illegals who cross, eventually. In San Diego, agents catch about 400 each day. They put most on a bus and return them to Mexico. But will that teach them a lesson? Persuade them not to try again? Of course not.
They keep trying because they want the better life that America offers. We talked to several illegal immigrants who had just been caught; all of them said they were going to keep on trying until they got in.
"Better work, better opportunities, more money," one captured illegal immigrant said. "They can catch me one, two, three, four, five times. Ten times. I'm going to cross."
Another said he'd keep trying until he got there with his family. "It doesn't matter to me. I'll cross again and I'll cross again. That's all."
A Brookings Institute survey of thousands of migrants who came to the U.S.-Mexico border found that more than nine out of 10 were able to enter, if not on the first try then on the second or third try.
And even if we built an impenetrable fence, one that's a mile high, it would only solve part of the problem, because lots of undocumented migrants don't sneak in. In fact, nearly half of illegal immigrants who are now in America came here legally through border checkpoints or they flew here and overstayed a tourist visa or a student visa.
A fence won't have any effect on them.
The 9/11 terrorists came here on tourist and student visas. They flew to America, legally. And yet you taxpayers continue to pay for construction of the border fence.
In an interview with "20/20," Drew Carey, who hosts Reason TV, said, "I don't know how anybody can't see that this stupid fence isn't a waste of money."
When Hunter retired from Congress this year, his son Duncan D. Hunter won election to his seat in the fall. He agrees with his father that we need a barrier on the southern border.
"What is it worth to the American people to not have another 9/11?" he said.
But wait a second. The border wall wouldn't have stopped 9/11.
"No," Hunter said. " But it might stop the next 9/11, or something like it."
But if it's good to wall off America, why just a wall on part of the Mexican border? What about the northern border? According to the Department of Homeland Security, last year more illegal Middle Eastern nationals were caught crossing from Canada than from Mexico.
And if we wall off Canada, we're still not covered. What about the miles of East and West Coast beaches? Are we going to have machine guns on the beaches?
The elder Duncan Hunter said that was silly. "Nobody's ever suggested doing anything mean. I think the message is this, if you want to come into the United States, which has the biggest front door in the world, you've got to knock on the front door."
But Carey points out, America doesn't make it easy to knock.
"It's so hard to get a guest worker permit and all this stuff. There's so many red tape hoops you have to jump through. It's easier to sneak across the border. We have to change it so the easiest, simplest thing isn't to sneak over the border. It should be if you want a job, you can come here and work. Get your papers and come in here and work."