Changes

| death_cause=Pulmonary fibrosis  

| death_cause=Pulmonary fibrosis  

| resting_place=

| resting_place=

| nationality= [[Mexican-American]]  

| nationality=[[Hispanic]]  

| party=[[Democratic Party|Democrat]]

| party=[[Democratic Party|Democrat]]

| spouse =Sylvia Santos

| spouse =Sylvia Santos

A native of [[Laredo]], Santos was one of four children of Mario Santos, Sr., and the former Rosemary Moore, both of whom are deceased.<ref name=obit/> He graduated in 1959 from Martin High School  in Laredo and obtained an Associate of Arts from Laredo Community College,  then known as Laredo Junior College and currently named Laredo College. In 1963, he obtained a bachelor's degree in economics and a minor in history and government<ref name=rgarcia/> from the Kingsville campus of [[Texas A&M University]]. He became a probation officer, first for juveniles and then adults.<ref name=obit/> In 1963, he received an instructor's certificate from the Texas Commission on Law Enforcement Standards and Education. In 1967, Santos attended the Juvenile Officers Institute at the [[University of Minnesota]].<ref name=rgarcia/>

A native of [[Laredo]], Santos was one of four children of Mario Santos, Sr., and the former Rosemary Moore, both of whom are deceased.<ref name=obit/> He graduated in 1959 from Martin High School  in Laredo and obtained an Associate of Arts from Laredo Community College,  then known as Laredo Junior College and currently named Laredo College. In 1963, he obtained a bachelor's degree in economics and a minor in history and government<ref name=rgarcia/> from the Kingsville campus of [[Texas A&M University]]. He became a probation officer, first for juveniles and then adults.<ref name=obit/> In 1963, he received an instructor's certificate from the Texas Commission on Law Enforcement Standards and Education. In 1967, Santos attended the Juvenile Officers Institute at the [[University of Minnesota]].<ref name=rgarcia/>

==Political career==

==Political career==