U.S. Sen. Marco Rubio (R-Fla.) welcomed the decision
Sentencing follows accepted plea offer
Agreement signed at Global Equality Caucus meeting in Argentina
Annual event takes place in Swiss resort town of Davos
Brandon Wolf is Equality Florida's press secretary
Massacre victims were inside single classroom
Homosexuality remains criminalized in West African country
Carney cites impact on youth, public health, law enforcement
Police say shooting was random and unprovoked
Staff discovers graffiti on walls, doors