While tragic, Abu Akleh's death wasn't deliberate, as found by multiple investigations. The IDF's probe — which included the US — thoroughly investigated the incident, while critics of Israel have been quick to jump to conclusions. The FBI's investigation will only waste time and damage the alliance between the two countries.
The fact that the US is now launching an official investigation into Shireen Abu Akleh's death means that it likely has credible evidence that a crime was committed. This long overdue probe is an important step toward accountability for the frequent and relentless Israeli human rights abuses.