Dozens of US legislators have signed onto a letter demanding the FBI investigate the killing of Al Jazeera journalist Shireen Abu Akleh, Congressman Andre Carson said, hours after Israel’s military said it will not launch a criminal inquiry into the incident.

Abu Akleh, who held US citizenship, was fatally shot by Israeli forces in the occupied West Bank last week, sparking global outrage and widespread calls for an independent or United States-led investigation.

“As we all continue to mourn the loss of this great journalist, fellow American, who was tragically killed while on assignment, we want answers,” Carson, who is helping lead the congressional letter, told Al Jazeera in an interview on Thursday.

“And we need to ensure that these answers are accurate, that they are transparent and that they are timely.”

The letter, first revealed by The Intercept earlier this week, calls for the US government to be directly involved in any probe into the fatal shooting of the Al Jazeera journalist.

“Given the tenuous situation in the region and the conflicting reports surrounding the death of Ms. Abu Akleh, we request the State Department and the Federal Bureau of Investigations (FBI) launch an investigation into Ms. Abu Akleh’s death.

“We also request the US Department of State determines whether any US laws protecting Ms. Abu Akleh, an American citizen, were violated,” it reads. “As an American, Ms. Abu Akleh was entitled to the full protections afforded to US citizens living abroad.”

The statement is addressed to Secretary of State Antony Blinken and FBI Director Christopher Wray.

Carson told Al Jazeera that the letter, which is still circulating on Capitol Hill to get support, has more than 55 co-signers already, describing the tally as “huge”.

“The State Department called her killing an affront to media freedom. I couldn’t agree more,” Carson said. “As the world’s leading democracy, we have a responsibility to protect the free press, not just in our own country but around the world.”

Family wants answers

President Joe Biden’s administration has condemned the killing and called for an investigation but said it would trust Israel to conduct the probe.

State Department Spokesperson Ned Price said last week that Israel has the “wherewithal and the capabilities to conduct a thorough, comprehensive investigation”, adding that “those responsible for Shireen’s killing should be prosecuted to the fullest extent of the law”.

The State Department did not respond to Al Jazeera’s request for comment on Thursday on the Israeli military’s statement.

US Secretary of Defense Lloyd Austin met with his Israel counterpart Benny Gantz earlier in the day, and a Pentagon readout describing their talks did not make any mention of Abu Akleh.

Asked by Al Jazeera during a briefing whether the subject was brought up during the meeting, Pentagon Spokesperson John Kirby said that Austin welcomed Israel’s “intent statement” to investigate.

“The government of Israel – it’s not for the Israeli military – I believe it’s in their Ministry of Interior, and they have stated a clear intent to investigate and the secretary [Austin] welcomed that investigation,” Kirby said. “And obviously, we look forward to seeing what the investigation finds out.”

Abu Akleh’s family has urged the US government and international community to step in and ensure an independent probe after the Israeli military said it would not investigate.

“We were expecting this from the Israeli side. That’s why we didn’t want them to participate in the investigation. We want to hold whoever is responsible for these acts accountable,” the family said in a statement to Al Jazeera.

“We urge the United States in particular – since she is a US citizen – and the international community to open a just and transparent investigation and to put an end to the killings.”

US aid to Israel

On May 13, Israeli police attacked Abu Akleh’s funeral procession in Jerusalem and beat pallbearers carrying her coffin with batons in scenes that spurred further anger and calls for accountability.

Palestinian rights advocates have been urging Washington to condition or restrict US aid to Israel over the killing of Abu Akleh and other Israeli rights abuses – an idea categorically rejected by the Biden administration.

The Al Jazeera journalist is the second American citizen to be killed by Israeli forces this year. In January, 78-year-old Omar Assad suffered a stress-induced heart attack after he was arbitrarily detained, bound, blindfolded and gagged by Israeli forces.

Israel receives $3.8bn in US military aid annually, and this year Washington added another $1bn in assistance to “replenish” Israel’s Iron Dome missile defence system after the May 2021 Gaza conflict.

Human Rights Watch, Amnesty International and Israel’s B’Tselem, among other rights groups, have accused Israel of committing apartheid against Palestinians – findings that have been rejected by the Israeli and US governments.

“There are many people who are calling [for] deeper scrutiny as it relates to support for Israel,” Carson said on Thursday. “Israel has been a strategic partner of the United States. I think that when we send money, we have to make sure that folks are being held accountable.”

He stressed that the US has a role in ensuring accountability for the killing of Abu Akleh.

“She deserves justice. Every American killed abroad is entitled to our protection. Every human killed – American or not – deserves justice, Palestinians included.”