She is a legal anthropologist who has conducted fieldwork in El Salvador since 1998 and with Salvadoran immigrant communities in the United States since 2004. Her multidisciplinary expertise lies at the intersection of Latin American studies, migration studies and border theory, law and society, and labor studies. Her recent work focuses on mass detention and deportation as components of the regime of mass incarceration in the contemporary United States, exploring how these systems uphold mechanisms of labor exploitation and intersectional oppression. Hallett is also an engaged public anthropologist with a commitment to human rights and social justice movements.