Law enforcement killed a suspected assailant who injured nine people at Ohio State University after plowing a car into a campus crowd and attempting to stab survivors with a butcher knife, news services reported Nov. 28.

Law enforcement officials have reported the suspect’s name is Abdul Artan, an 18-year-old Somali refugee, and student at the University. Artan reportedly immigrated to the United States in 2014 as a legal permanent resident, officials said.

The attack follows an election season in which immigration, and especially U.S. policy towards immigrants from the Middle East, played a central role in both presidential campaigns.

In light of the public controversy generated by the admission of Syrian refugees into the United States, the Congressional Research Service provided a policy brief of the country’s refugee admissions and resettlement process, summarized below.

Refugee Ceiling and Regional Allocations set by President

 Under the Immigration and Nationality Act (INA), the president sets the maximum number of refugees the United States will receive each year, following consultations with the Cabinet and Congress.

President Obama pledged to admit 10,000 Syrian refugees in the fiscal year 2016, which he did the final week of August, CRS said. Refugees must be approved by officials from the State Department’s Resettlement Support Center and the Homeland Security Department’s U.S. Citizenship and Immigration Services (USCIS).

USCIS has called its refugee screening process as the “most robust of any population screened by” the agency. The agency collects biometric data and screens applicants against the Consular Lookout and Support System (CLASS), as well as those maintained by the Federal Bureau of Investigation and National Counterterrorism Center.