The justice department will not seek the death penalty against Ahmed Abu Khattala, the suspected Libyan militant charged in the Benghazi attacks that killed a US ambassador and three other Americans, federal officials announced on Tuesday.

The department revealed its decision in a brief court filing that offered no additional explanation.

In a separate statement, spokeswoman Emily Pierce said the attorney general, Loretta Lynch, had made the decision after consulting with prosecutors. Pierce said the department remained “committed to ensuring that the defendant is held accountable” for the 2012 attacks.

Khattala’s attorneys had been imploring the justice department to remove the death penalty as a possibility should he ultimately be convicted of any capital crimes in a trial. With the death penalty now off the table, he would face a maximum sentence of life in prison if convicted.

“It was a decision that was the correct decision but was also a courageous decision, so we’re pleased,” said one of his attorneys, Eric Lewis.

Khattala, captured by US special forces in Libya two years ago and brought to the US aboard a navy ship, has been awaiting trial in federal court in Washington in connection with the September 2012 violence at a diplomatic compound in Benghazi.

Prosecutors have described him as a ringleader of the attacks, which quickly emerged as a political flashpoint and became the topic of congressional hearings involving Democratic presidential candidate Hillary Clinton, secretary of state at the time of the rampage.

The 18-count indictment arises from a burst of violence that began the night of 11 September 2012, at a diplomatic compound, an attack prosecutors say was aimed at murdering American personnel and plundering maps, documents and other property from the post. Ambassador Chris Stevens was killed, along with Sean Patrick Smith, a State Department information management officer.

The charges against Khattala include murder of an internationally protected person, providing material support to terrorists and destroying US property while causing death. He has pleaded not guilty.

The case represents one of the most significant tests of the Obama administration’s commitment to prosecuting terror suspects captured overseas in US civilian courts.

The trial is also likely to focus fresh attention on security at the diplomatic compound, an issue that provoked immediate political concern and was the subject of a daylong hearing last year organized by a congressional select committee investigating the attacks.

Since arriving in the United States, Khattala has made multiple court appearances alongside his lawyers. He sought unsuccessfully to have the case against him dismissed, and a separate request for him to be returned to Libya was also denied.

The decision comes at a time of heightened scrutiny of death penalty protocols at the state and federal levels. Executions in the federal system are exceedingly rare; the execution of the last defendant put to death was in 2003. The justice department has said it is reviewing the policies, though nothing has been publicly announced, and Barack Obama has said he is “deeply concerned” about the death penalty’s implementation.

At her January 2015 confirmation hearing, Lynch said she thought the death penalty still could be an effective punishment.