This article originally appeared in The Dispatch on December 22, 2025.
Every year, the State Department randomly selects approximately 50,000 immigrants from a pool of roughly 20 million applicants for admission through the Diversity Visa Program lottery. Those selected undergo the same security screening applied to all immigrant visa categories: FBI fingerprint checks, consular interviews, police certificates from every country of residence, medical examinations, and—since 2019—disclosing all their social media account handles.
The program was created by Congress in 1990 to extend permanent legal immigration pathways to countries underrepresented in family and employment-based admissions, but it has faced criticism as a security vulnerability. The recent mass shooting at Brown University and the murder of a Massachusetts Institute of Technology professor, incidents police say are linked, have renewed those concerns and prompted the Trump administration to pause the program within days of the attack.
The alleged shooter, Claudio Manuel Neves Valente, was a 48-year-old Portuguese national who Homeland Security Secretary Kristi Noem said obtained a green card through the lottery in 2017. He had no prior U.S. criminal record. On December 13, 2025, police say, he shot and killed two Brown students—Ella Cook, 19, and Mukhammad Aziz Umurzokov, 18—and wounded nine others at the university’s Barus & Holley engineering building. Two days later, he allegedly killed MIT Plasma Science and Fusion Center director Nuno Loureiro, 47, at Loureiro’s Brookline home. Police found Neves Valente dead by suicide Thursday. After Neves Valente’s immigration pathway was made public, Noem announced that U.S. Citizenship and Immigration Services (USCIS) would pause the DV program, stating that Neves Valente “should never have been allowed in our country.”
The known facts of the case present a complicated picture. Portugal is a NATO ally and enjoys access to the Visa Waiver Program because it presents minimal security risks. As a recipient of the Diversity Visa, Neves Valente underwent vetting identical to all other immigrant visa categories. One of his targets was Loureiro, a former classmate from Instituto Superior Técnico in Lisbon, where Neves Valente’s teaching assistant contract was terminated in February 2000. The questions at hand now are whether any screening process could have detected a decades-old personal vendetta, and whether the DV lottery creates security vulnerabilities distinct from those of other visa categories.
