Members of a rival cartel gunned down Edgar Beltran Guzman, one of El Chapo's sons, in a Mexican shopping mall parking lot in 2008. Police found more than 500 bullet casings at the scene.
Last year, authorities arrested Guzman's father-in-law in Sonora, Mexico, charging him with drug-related crimes.
But not all of the focus on Guzman's family has been tied to organized crime.
In September 2011, word eked out that Guzman's beauty-queen wife, Emma Coronel -- a citizen of both the United States and Mexico -- had given birth to twin girls at a hospital in Lancaster, California.
About a year later, authorities arrested Alejandrina Gisselle Guzman Salazar, one of El Chapo's daughters, at a border crossing in San Ysidro, California. She was deported back to Mexico several months later.
Her attorneys said she was pregnant and had been coming to the United States to have a baby.