For Lt Leon, the goal is not just to prevent illegal immigration, it's also to halt crime and save lives. Each year hundreds of bodies are found on the Spanish coastline, but many more are believed to die at sea.It has frequently seemed that Spain is taking defense against illegal immigration more seriously than America is.
"We can't allow these criminal gangs to profit from the trafficking," Lt Leon says. "This 1,000-mile journey has claimed too many lives already."
He may be getting some unexpected help from a downturn in the Spanish economy, which pushed unemployment to 13.4% in November.
During a visit to the southern province of Almeria on Tuesday, the Secretary of State for Migration, Consuelo Rumi, said Spain's rising unemployment rate was contributing to the fall in illegal immigration.
"Work is the principal pull factor for foreigners to enter Spain," she said.
But Lt Leon argues that the main pull factor is the difference in living standards - and that is unlikely to change dramatically any time soon. [Satellite helps fight illegal immigration, By Vanessa Buschschluter,BBC News, Jaanuary 25, 2009]