this is a special edition of "nightline," gangland. a place where there is a homicide nearly every hour, even grieving families aren't safe. we're right there for gun fire at a wake. and we take you inside this over crowded jail. brimming with allegedly violent gangsters. now the gangs of el salvador are metastasizing across america, operating in nearly every state in the nation. this teenager hoping for a new life here in the u.s. and what he learned just hours ago. >> this special edition of "nightline," gangland, will be right back.

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mercedes-benz c-coupe, with its athletic prowess and sleek new body. it doesn't just raise the bar... ...it completely crushes it. the all-new c-class coupe. mercedes-benz. the best or nothing. this is a special edition of "nightline," gangland. >> tonight we take you inside one of the most dangerous countries on earth, a place where gangs control entire neighborhoods and they're now operating in nearly every corner of america. families on both sides of the border caught in a toxic cycle of violence.

a special edition of "nightline" gangland. it's the middle of the night in the murder capital of the world. >> something's going on in the area. [ dog barking] >> we're in el salvador on patrol with armed to the teeth cops. >> this is a very dangerous place. >> reporter: they take us to this run down police station where they're holding allegedly vicious combatants in this country's all out gang war. >> how many people are they holding here? 169 people in here? [ speaking foreign language] >> reporter: not sure if you can get a sense of how small this is

but it's tiny. they're just housed on top of each other. what does it say on your forehead? 6-6-6 he says. >> deoblow. >> they're only supposed to be in here for 72 hours. how long have you been here? >> one year. >> reporter: do you ever get to step outside? >> no. >> reporter: by young people who feel they have no choice but to join a gang. how strong is the bond with your other gang members? ♪ this is the war next door. in tiny el salvador, just over 1500 miles south of the u.s. border, there's nearly one homicide an hour.

>> shootings and stabbings. ms 13 has left a trail of victims throughout greater boston. >> reporter: living in our neighborhoods here in southern california. >> reporter: and now they're exporting death directly into amair ameri amare cu. they're active in 46 states. >> kill, rape, control. >> reporter: here in the el salvador en capital, they've carved up the city into warring factions. this is our translator, raphael, who like the cops doesn't want gang members seeing his face and targeting his family. every night this team from the local morgue heads out to collect the bodies. it's only 9:00 and the body count is already at seven. seemingly everybody is at risk

here. we find a 23-year-old named carlos shot inside his own home after ordering a pizza. this is his mother. >> he was her baby. >> reporter: she insists her son wasn't even in a gang. >> every night, 24-7. ♪ >> reporter: so, we're heading into a neighborhood controlled by barrio 18. we're going to talk to the gang leader. we had to get advanced permission to enter, because if

you don't, you're in serious danger. >> reporter: we're here to meet the local gang leader who goes by pablo which is spanish for nail. does that mean you have to resort to violence? >> if you need to get hard, you go hard. >> reporter: if you walked into an ms area -- >> they kill you. they maybe kill us too. >> reporter: so, that's how fierce loyalty is, you will kill somebody from a rival gang? as a boy, he moved to virginia from a gang and then got deported back to el salvador where his gang career continues and now he wants to escape back into america in part to escape gang life because he's tired of

taking orders from leaders who are in prison. who will they ask you to kill? >> i don't know. maybe a cop. maybe someone else. >> reporter: and you don't eeskeesk even know why. >> just do it. >> reporter: that's crazy? >> yeah. >> reporter: and if you don't, they will kill you? >> maybe. >> the weapons that are mostly used by gang members are pick axes, machetes and guns. >> reporter: we're with monisha kylie from canada, part of a team of archeologists who help identify victims in unmarked graves often dismembered. do you ever lose sight of the fact that this was a human life as vivid as our own? >> especially working here in el

salvador, there's death all around us. we're used to this. >> reporter: this is a brisk, efficient processing center for human misery. one technician tells us they see an infinity of death. every day families come to the morgue to search for the missing and to identify and collect the dead. we meet era, her 17-year-old son was killed last night. just two months ago, one of her other sons was murdered by the gang. at which point she says she applied for asylum in america for her family. she's still waiting for a response.

>> reporter: coming up, she invites isto her son's wake where we are completely unprepared for what happens next. and we will meet a teenager who escaped the gangs by fleeing to america where he is now fighting to stay. if you have moderate to severe rheumatoid arthritis, and you're talking to your doctor about your medication... this is humira. this is humira helping to relieve my pain and protect my joints from further damage. this is humira helping me go further. humira works for many adults. it targets and helps to block a specific source of inflammation that contributes to ra symptoms. doctors have been prescribing humira for over 13 years.

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♪ >> reporter: this grieving mother is holding a wake for her 17-year-old son, alexis. murdered by gangs just last night. and right in the middle of the service -- [ gun shots] [ screaming] ♪

>> reporter: right there, clinging to loved ones, the likely target, her only remaining son. the preachers resume, an act of defiance. >> a car stopped by here and just started shooting. >> reporter: you sound nervous. >> i am. what are we doing? >> going to go check with

police. >> they won't touch the guys. the guy's already gone. this is day by day what people do here. happens every day. >> reporter: and for this mother and her only remaining son, the danger is not over. they have to get through the burial in the morning. the next day we learn that the best hope for are avoiding violence at the funeral may come from a man accused of having close ties to the gang, the mayor. he denies these allegations but with our cameras rolling. he actually call as gang leader and asks the gang to stand down. [ speaking foreign language]

♪ ♪ >> reporter: the unbroken cycle of madness in el salvador has provoked a massive flood of illegal immigrants cross nothing to america, inhadcluding 10s of thousands of unaccompanied

minors but once here they find themselves targeted by the very same gangs. we're with undercover cops in los angeles. this is where the gangs actually started before spreading throughout the country and the continent. >> right in the middle of this neighborhood is a mural with a machine gun celebrating a gang. ms 13 and barrio 13 allegedly engaging in drug dealing and prostitution and then sending the proceeds back to their leaders in el salvador. >> so, all of these businesses are, odds are they're all paying p protection money to the gang. >> reporter: when did you get into trouble with the gangs? when did they first start threatening you? >> when i was six and five years, i think. >> reporter: this is the young

man who made the parls journey to america alone at age 13. and then they hunted down his mother, sister and little brother. >> they tried to kill my family my mother and my little brother and my sister. >> reporter: it's very sad. >> yeah. i miss them. >> reporter: his very survival may hinge on getting asylum here in america. >> his very life is at stake with these legal proceedings. >> reporter: so, the stakes couldn't be higher? >> no, i don't think that they could. >> reporter: if you don't get asylum and you have to go back, what do you think will happen? >> they're going to kill me. me and my family. >> reporter: we went looking for

francisco's family in el salvador and found them living in fear. we can't go to where she lives because she moves around constantly. she basically lives in hiding from the gangs. so, we're picking up from a mcdonald's and taking her to a safe location to do the interview. francisco's mother and siblings tell us how gang members burst into their apartment one night firing shots. that's a gun shot wound? wow. >> reporter: so, you put your leg up to protect her head from the gun? did you tell the cops? >> no. >> reporter: why not? >> reporter: are you still scared?

you miss your brother? no kid should have to live like this. the el salvadoren government is now escalating the fight, declaring them terrorist organizations but some say the police are going way too far. they've been accused of forming death squads and the gangs are sending the murder rate to record levels. are you losing the fight against the gangs? >> no. i don't think so. >> reporter: we asked one of the country's top cops about the government's current crack down. even after this very difficult year, so many people so scared and dead, you still believe this is the right strategy? >> yeah, i think we're in the right way, yeah. >> reporter: on one of our final days in el salvador, a top gang leader agrees to speak to us. he says the government doesn't have control.

he and the gangs do. >> reporter: is this just going to get worse? what's the solution? he says the government is daring us into war. and as a show of force right on camera, he announces a ceasefire between ms 13 and barrio 18. the next night, we go back to the morgue and crickets. this is really a stunning illustration of the power of the gangs. the morgue is at a stand still. no bodies. within days, however, the violence resumes with so many lives hanging in the balance. coming up, judgment day for francisco. >>i iu'm a little bit nervous. >> reporter: and his struggle to stay in america. if your family outing is magical for all the wrong reasons. you may be muddling through allergies.

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♪ and finally tonight, a huge development for francisco, the