Louisiana Attorney General Jeff Landry is expected Tuesday to announce his long-awaited decision about potential state criminal charges against two police officers in the Alton Sterling case. 

On Monday evening, Landry's office put out a notice that he would provide an update in the case. Earlier in the day, law enforcement sources said leaders within the Baton Rouge Police Department and State Police were notified that an announcement about the decision was expected. 

Landry took over the case last May after the U.S. Department of Justice declined to bring federal civil rights charges against the two white police officers, Blane Salamoni and Howie Lake II, who were involved in the fatal shooting of Sterling, a 37-year-old black man, in July 2016 outside a convenience store. 

L. Chris Stewart, an attorney for the Sterling family, confirmed that family members will meet with Landry Tuesday at 9 a.m. in Baton Rouge. Landry will hold his news conference at 10 a.m., according to a news release. 

In recent months, there have been occasional calls by Baton Rouge elected officials for Landry to finish his investigation, arguing people in the city are anxious to hear his verdict. But Landry has defended his process, saying he needed to be thorough in his own review of whether the officers should be charged under state law. 

"When we took over the case that was day one for us," Landry said in a March interview. "It was over 360 days for the family and the community, but it was day one for us. We are moving as effectively and efficiently as we can, but I'm not going to be rushed to judgement on such a very important topic... We're going to make sure that we go through the facts and the evidence as thoroughly as the federal government did."

He also said that when they do make the decision on charges, he plans to do so in a way that "has the ability to answer everybody's questions."

Attorney General's Office staffers were told not to report to work at the Livingston state office building on Tuesday, according to a department-wide email that told employees to treat the day as "an unexpected day off" if they do not have other business outside the office.

The email included new security protocols described as being put into effect for the office indefinitely starting Wednesday. Security will remain tight, and staffers were admonished not to respond to any "questions/comments from non-employees outside the building."

The State Police were also mobilizing additional manpower ahead of Tuesday's announcement. A law enforcement source said the agency was bringing in a mobile field force normally assigned to the northern part of the state, with even more backup on standby. Some troopers were being told to pack eight days worth of clothing.

Baton Rouge police, meanwhile, planned to begin so-called "protest operations" at 6 p.m. Monday, according to an agency email, seeking to avert a repeat of last summer, when protesters began to gather the night before federal authorities announced that neither officer involved in Sterling's shooting death would face civil rights charges.

Community activists have called on Baton Rouge Police leadership to fire Salamoni and Lake, arguing descriptions of unreleased video of the incident raise questions about whether the officers followed BRPD policy in their interactions with Sterling.

Mayor-President Sharon Weston Broome joined those calls last spring, saying Salamoni — the officer who shot Sterling — deserved to be terminated. Broome said information released by DOJ to her and former Police Chief Carl Dabadie Jr. included "very disturbing details" about Salamoni's actions. 

But BRPD officials have countered that their policies call for any criminal investigation to be concluded before decisions are made about whether an officer should be disciplined, allowing for due process. Once the probe is done, newly appointed Chief Murphy Paul makes the call about whether the officers lose their jobs, face lesser punishment, or are not disciplined at all. 

On Monday, Broome said she is aware of the planned announcement in the Sterling case and will hold a news conference after they learn the AG's decision to "update the public on our plan of action."

"Our city has patiently awaited this decision, but no matter the outcome, we will walk through it together as a community," Broome said in a statement.

Kyle Kershaw, the attorney for Lake, said he has not been informed of what decision will come from Landry. "I don't think he violated police procedure, I definitely don't think he violated the law," he said.

On July 5, 2016, the two officers responded to an anonymous call about a black man in a red t-shirt selling CDs who had threatened someone with a gun outside the Triple S convenience store on North Foster Drive. Sterling matched the description. 

The ensuing encounter — from when Lake first arrived followed shortly after by Salamoni, to the final shot fired at Sterling by Salamoni — lasted less than 90 seconds. 

The interaction was caught on cell phone video by two witnesses and quickly went viral through social media. Nightly protests followed, as did later discussions about BRPD's larger relationship with the black community. 

The encounter was also caught on other video and audio, such as surveillance tapes and body camera recordings, which have not yet been made public, but were part of the federal probe. Sources last spring said the video shows Salamoni almost immediately drawing his service weapon and pointing it at Sterling's head, while also using the word "bitch" and threatening to shoot him. 

Lake was the first officer to arrive, with Salamoni coming in with his gun drawn while the other officer issued commands, sources have said. According to federal authorities, Sterling didn't initially comply with Lake's commands to put his hands on the hood of a car as the officer approached. 

While Sterling does put his hands on the car, he later takes them off. Lake then attempted to shock Sterling with a Taser, causing the man to fall to the ground. When Sterling — who was 6 foot 3 inches weighing more than 300 pounds, larger than both officers — tried to get back up, Lake used the stun gun again, but was unsuccessful, federal investigators said last spring. 

Salamoni then wrestled Sterling to the ground, and during the struggle, the officer yelled that Sterling had a gun, according to the cell phone videos. 

At that point, Salamoni fired his weapon three times at Sterling's chest. While Sterling appears to try and sit up, Salamoni fired three more shots into Sterling's back. Both officers later told BRPD detectives that they believed Sterling was reaching for a gun.

A loaded revolver was recovered from Sterling's pocket. Sterling, a convicted felon, was unable to legally carry a firearm. 

In explaining their decision to not press charges in May, federal prosecutors pointed to Sterling's unpinned right arm, which was moving during the struggle on the ground. They said the evidence could not clearly show where Sterling was moving his arm and were, therefore, unable to prove Salamoni didn't have a genuine and reasonable fear for his life when he pulled the trigger on his service weapon.

But attorneys for the Sterling family have said they were most dismayed by the descriptions of how Salamoni first approached Sterling, emphasizing that they saw his actions as escalating the incident. These moments were described to them by federal authorities in private meetings, they said last spring, portraying the federal officials as shocked by Salamoni's actions when he first encountered Sterling. 

John McLindon, a lawyer representing Salamoni, declined to comment on the details of the incident or the pending decision. However, in May after the federal government's decision not to prosecute, McLindon said he felt that decision was appropriate. 

"Every agent that worked on this case said that there was not enough evidence here to prosecute," McLindon said in May. "That's what I always felt belonged and it was good to hear it from the government."

Landry took over the case after East Baton Rouge Parish District Attorney Hillar Moore III removed himself, citing long-standing relationships with Salamoni's parents, who have both served as Baton Rouge police officers.

Both officers have been on paid administrative leave since July 5, 2016. 

Follow Grace Toohey on Twitter, @grace_2e.