The law, a version of which was enacted in Florida in 2005, allows for individuals to use deadly force -- even outside their home -- if they feel threatened.
Since the shooting of 17-year-old Trayvon Martin, Republican leaders have called the killing a tragedy but argue that the law in question did not actually apply to this case.
Still, Schumer wrote in a letter to Attorney General Eric Holder on Sunday that the laws themselves should be investigated.
"These laws seem to be encouraging vigilantism by allowing individuals to use deadly force as a first resort," Schumer, D-N.Y., said in a statement.
Schumer asked Holder's department to probe whether the laws "are creating more violence than they are preventing," and whether potential murders are "going unprosecuted" because of them.
He estimated that 23 states have some form of this law.
Schumer cited statistics in Florida showing that before the law was approved, the state averaged 12 justifiable homicides per year. The average subsequent to the law's enactment was 33.