The construction of the wall between the U.S. And Mexico is not a new idea since it has been going on for three decades. Gettyimages/Luis Diaz Devesa

The Border Patrol failed to count hundreds of migrant deaths on U.S. soil, a CNN investigation found Monday. More than half of the uncounted deaths reportedly happened in the past four years.

According to the CNN report, the surge in deaths began after the 1994 immigration initiative that included border enhancement as an integral part of the administration's measure to reform the immigration system. In the same year, the Border Patrol decided to begin building barriers in urban areas to push border crossers out into more remote and dangerous terrain.

But within a year or two it became obvious that the dangers weren't deterring crossers and the number of migrants dying on the border had jumped from dozens a year to hundreds, the report claims.

The Border Patrol launched a set of measures as part of the Border Safety Initiative in 1998, to warn migrants about risks, rescue those in trouble, and quantify border-crossing deaths. But this initiative left it up to leaders in each of the border sectors to decide which bodies to count and how, it said.

The U.S. Government Accountability Office, in 2006, found that the agency consistently understated the numbers in its reports to the government and didn't generally ask local law enforcement agencies and coroner's offices for their cases. Following this, the agency promised to establish liaison with local officials to obtain information on those undocumented migrant deaths in which the Border Patrol was not involved.

The CNN report stated that lawmakers faced very little political pressure even after that to push for more accurate numbers, though advocacy and humanitarian groups called for changes in policies to reduce border deaths.

But the families who lost their near and dear ones still feel powerless to complain either because they live outside the country or include members without documents.

According to the report, the Border Patrol officials chased 18-year-old Darwin Cabrera who illegally crossed into El Paso, Texas, in 2014,

The report stated the death of 18-year-old Darwin Cabrera who illegally crossed into El Paso, Texas, in 2014. As the Border patrol chased him, he dove into one of the canals flanking the U.S. side of Rio Grande River. Two days later, his body was found floating face down in the river.

Though the Border Patrol agents found his body, his death was not counted. The official tally of border-crossing deaths in their El Paso sector that year was 0.

CNN investigation found that, over the 16 years ended last September, at least 564 more people died while crossing illegally in the border region than the Border Patrol's tally of 5,984.

In Arizona, volunteers and local officials have compiled their own count of border-crossing deaths. It includes scores of deaths not included in the Border Patrol's official tally. The agency's undercount in the region has been persistent. As many as 422 deaths were reported by the agents over the last 16 years. More than half of the deaths the agency has not counted came in the last four years.

The report added that over the years, Texas' Rio Grande Valley has surpassed Arizona as the deadliest crossing point from the south. The gap between the Border Patrol's figure for migrant deaths and a larger count is 94 deaths over the past 15 years in the valley, CNN reports.

“That wall, it's not going to make a difference and if it does, it's going to create more deaths,” said Eddie Canales of the South Texas Human Rights Center.