Transcript for An inside look at the deadly toll on immigrants at US southern border
This is the border barrier in this area which was and is still is a major drug trafficking and human trafficking corridor. Reporter: Thousands of miles from Washington, sheriff mark Napier is on the frontlines of the border crisis. We know that somebody came here with a kid. There's children's clothing, diapers, a small container of baby oil. Reporter: For more than three decades, pima county, Arizona has been his home. The largest county on the southern border. But on the national stage, what happens here has become a political flashpoint. It's a very powerful, very powerful wall, the likes of which probably to this extent has not been built before. Reporter: Just yesterday, president trump at the border south of San Diego, signing a newly constructed section of the border wall and touting his campaign promise. Plus it's designed to absorb heat, so it's extremely hot. The wall is, you won't be able to touch it. You can fry an egg on that wall. Reporter: This, the latest spectacle in a debate that's dominated headlines and divided the country. Breaking news, the tense battle. The humanitarian crisis at the border. And perhaps most disturbing. A national emergency, citing an invasion on the border. It's a great political debate in Washington DC. It's great fodder for media but this is my home. This is where I live. Reporter: But from here, the lifelong Republican warns against simplistic bluster. The border is clearly a public safety threat to my county because of the drug and human trafficking that comes across that border. Public safety's not a partisan issue, it's not a political issue, it's quality of life, it's a human condition issue. These people still have forty miles of desert to traverse before they get to something that would resemble civilization where they can be picked up by somebody else. My deputies do recover almost 100 bodies a year in the deserts of this county. That taxes our resources, but it also pulls at my strings from a humanitarian standpoint. So far this year, year to date in 2019, we've recovered 92 suspected undocumented border cross remains. Reporter: Chief medical examiner Greg Hess and his team work to identify remains recovered in the desert. A reality he says has spiked since the early 2000s. We went from, again, 15 remains recovered to 75 in the year 2000. In 2001, it was 77. In 2002, it was 145. Reporter: On the exam table, the incomplete remains of an unidentified migrant discovered earlier this year. This person's a little bit on the older side. You can see, for example, right here on the spine, that happens as the spine compresses over time. Reporter: But with little to go on, Hess says, the odds of identifying this person in the next few years are small. That was somebody's father, that that was somebody's brother, somebody's son. That's a human being, and a human being probably driven by very desperate decisions in their home country to make a very dangerous and illegal ingress in the United States that cost them their lives. One thing that we do need to do, and the president's correct, is we need to secure our southern border. I do understand the desperation. But say, "This is not a safe activity. Do not try to come into this country illegally because you're going to victimized by criminals, by the environment and it's not a safe way to come into our country." Reporter: The vast majority of immigrants enter the country legally, including asylum seekers like angel Ramos. Last year, he and his son Fernando fled Honduras, and like many Central American families, says they had no choice but to take the risk. Reporter: They made the perilous three-month journey on foot, bus, and train to reach the U.S. Border. Unlike the hundreds of thousands who have crossed into the U.S. Illegally, angel says he wanted to do it the right way petitioning for asylum to U.S. Immigration officials at the Nogales port of entry. After a few days, immigration officials released angel and Fernando at this shelter in Tucson, Arizona. The two allowed to stay in the U.S. As their asylum case makes it through the courts. But new policies under the trump administration are making it harder for asylum seekers like angel to seek refuge. While immigration dominates headlines, a constant concern on the border is stemming the flow of illegal drugs. The majority coming through legal ports of entry. We are usually directly involved in finding or assisting other agencies in finding hundreds of pounds a year. You can imagine how much is probably getting through and how much is actually in this country right now. Reporter: Sergeant Patrick Hilliker is with the border interdiction unit at the pima county sheriff's department. This is basically the opiate epidemic that's going on right now with some fentanyl pills. This is approximately 14 pounds of heroin. This one in particular you can see they're in vacuum sealed bags and that's to contain the smell and make it so the dogs don't smell it. The southwest border has long been the primary entry point for heroin. In 2017, nearly a thousand pounds of heroin came through the Tucson sector. Hey frank, go ahead. I'm code 10. Copy that. They're still meeting? Right now we're with a unit watching what they believe is a stash house. If they see something that looks like there's some smuggling going on, we'll go try to stop the vehicle and talk with them. Any way you can think of smuggling narcotics into this country, it's been done. They will pay people into bringing this stuff up and it's quick money. Sometimes, there's elderly people that are doing it, younger people, different nationalities, different citizenships. It's just whoever they can contact, talk into it and exploit. We've found it anywhere in a vehicle you can think of. Radiators, fake battery compartments, fake flooring in the vehicle. They'll take everything out of the vehicle put in a fake floor, reweld it, paint it, put the carpet back over it, and put the seats back on and it's very difficult to find. We found what appears to be bricks of heroin inside of a backpack the subject was wearing. This is the backpack it was found in. We believe it's heroin, until we test it. Until we weigh it, we're looking at one, two, three, four, five kilos that didn't get to their destination or sold to the community. This is really the front line of a national issue, right here in our counties. Reporter: For Napier, these aren't far away threats but realities of his backyard. Nuances too often lost amidst the noise. We need to secure our border for public safety reasons, national security reasons, and human rights reasons. No one can argue past those three points. Let's get it done. Let's secure the border and look at comprehensive immigration reform that has a good public policy foundation.
This transcript has been automatically generated and may not be 100% accurate.