Rep. Pramila Jayapal (D-Washington) and Sen. Patty Murray (D-Washington) are calling on the Biden administration to conduct an independent probe into Israel’s killing of American activist Aysenur Ezgi Eygi, as officials have been relying on Israel’s own flawed investigation into her death.

In a letter addressed to President Joe Biden and Secretary of State Antony Blinken, the two lawmakers call for an “immediate, transparent, credible, and thorough independent U.S. investigation” into Eygi’s killing. They raise alarm that U.S. officials have allowed Israel to kill U.S. citizens in the past with impunity.

“We fear that if this pattern of impunity does not end with Ms. Eygi, it will only continue to escalate. It is imperative that the United States take concrete and decisive action to better protect American citizens,” the lawmakers said. They then asked the administration to indicate whether they will pursue an investigation and to release the knowledge they have of her killing within the next two weeks.

Sen. Bernie Sanders (I-Vermont) said that Eygi’s killing, as well as Israel’s bombings of its designated “safe zone” in Gaza this week, are the latest evidence that the U.S. must stop sending weapons to Israel.