Progressive U.S. lawmakers on Thursday joined relatives of Shireen Abu Akleh in demanding the Biden administration thoroughly and transparently investigate the Israeli military’s killing of the Palestinian-American journalist, with one congressman introducing a bill that would require such a probe.

“We want to know who pulled the trigger, and why,” said Victor Abu Akleh, a nephew of the 51-year-old Al Jazeera reporter, outside the U.S. Capitol. “And we want there to be accountability for the system that gave the green light, so that other families don’t suffer the way that we have. The reality, of course, is that in Palestine, our family’s grief is not unique.”

Speaking at the press conference, Rep. André Carson (D-Ind.) announced the Justice for Shireen Act, proposed legislation that would require the State Department and FBI to investigate Abu Akleh’s killing and publish a report on their findings.

“We need answers to hold the perpetrators fully accountable,” said Carson, who called the killing an “attack on the Fourth Estate, the free press, which is vitally important to our society.”

“From Day One the Israeli government has denied Shireen’s murder. There is no reason for them to be conducting an investigation,” he continued. “It makes it more important for our government to conduct our own investigation. Shireen needs justice. Every American killed abroad is entitled to our protection. Every human killed, American or not, deserves justice, Palestinians included.”

Demanding that the Biden administration investigate the killing of U.S. citizens by Israeli forces, Rep. Rashida Tlaib (D-Mich.)—who is Palestinian-American—said Abu Akleh’s death “was not an accident.”

Tlaib said it was “shameful” that “Shireen’s family is forced to come here and demand that the State Department and our government… hold her killers accountable and prevent this awful tragedy from repeating itself again and again and again.”

“Maybe, for some of my colleagues, they need to take out the word ‘Palestinian’ from ‘Palestinian-American’ for her life to matter,” she speculated. “We have different standards applied when it comes to Israel even as they kill Americans, including 78-year-old Omar Asad or… Rachel Corrie,” the 23-year-old International Solidarity Movement volunteer crushed to death in 2003 by an Israeli bulldozer while trying to prevent the destruction of Palestinian homes in Gaza.

“When Americans are killed abroad it is more or less standard procedure for our government to open an investigation. But when the murderers wear Israeli uniforms, there is complete silence,” Tlaib lamented. “Poor Rachel Corrie’s family to this day has been waiting for justice since 2003 and still nothing… I knew when her family didn’t get justice that Israel would have impunity for future killings of Americans.”

Reps. Betty McCollum (D-Minn.), Ilhan Omar (D-Minn.), Ayanna Pressley (D-Mass.), and Alexandria Ocasio-Cortez (D-N.Y.) also spoke at the press conference. Ocasio-Cortez asserted that President Joe Biden should meet with Abu Akleh’s relatives.

“Shireen and her family deserve to be treated the same way that any other American would be in this situation,” the Squad member insisted. “An American journalist was killed abroad by a foreign army, by a sniper. This situation demands a thorough and objective investigation.”

In a Wednesday Washington Post opinion piece, Lina Abu Akleh, Shireen’s niece, noted that multiple investigations—including by United Nations officials and media outlets such as the Post and The New York Times—all concluded the journalist was killed by Israeli fire.

“Yet I read with bewilderment a statement that the Biden administration issued on July 4,” she wrote. “Based on reviewing and summarizing the Israeli government and Palestinian Authority’s investigations, the United States concluded that Israel was likely responsible for my aunt’s killing, but that there was no reason to believe that it was intentional.”

“I was alarmed. Why was the Biden administration repeating Israel’s spin, given the lengths that the Israel military has gone to manipulate the events around Shireen’s killing?” she asked. “Israel initially blamed Palestinians, circulating a misleading video that human rights organizations quickly debunked. Then, an Israeli military spokesman went so far as to suggest that journalists such as Shireen are ‘armed’ with cameras.”

Abu Akleh lamented that a Wednesday meeting with U.S. Secretary of State Antony Blinken failed to secure a commitment to investigate her aunt’s killing.

“We fully understand the U.S. government’s role in fueling the belief of Israeli leaders and soldiers that they enjoy impunity for their actions,” she wrote. “Yet this is why it is all the more urgent for my family to impress this message upon the administration: Biden can stop this pattern. He can pledge to pursue meaningful accountability for my aunt, starting with a commitment to conduct an independent U.S. investigation in Shireen’s case.”