The Democrats hoping to challenge Ms. Collins, a vulnerable Republican, have seized on the fatal incident, drawing attention to her record on immigration matters.
Kristi Noem, the former homeland security secretary, said five months ago that the Trump administration would “rapidly” deploy body cameras to immigration agents across the country. About half still don’t have them.
The father of Joan Sebastian Guerrero, the man fatally shot by a federal immigration agent on Monday, said his son had been working two jobs to support his wife and daughter.