The office received the evidence and police reports regarding Sgt. Shawn Scott's shooting last week and is evaluating the circumstances of the death, Chief Deputy Distict Attorney Dustin O'Brien said.
The office has yet to receive the police reports for Officer Jeremy Hill's fatal shooting, he said.
New Mexico State Police are investagating both of the shootings.
O'Brien said District Attorney Rick Tedrow is planning to use a grand jury but the decision is not final.
If the case goes before a grand jury it doesn't mean local prosecutors have taken a position on whether or not the local officers commtted a crime, he said.
Scott fataly shot Mark Chavez, 49, outside a home on Loma Linda Avenue in Farmington on Jan. 1.
Chavez was holding a "blunt impact weapon" and walking toward Scott, New Mexico State Police said. The agency has declined to elaborate on what weapon Chavez had.
Chavez had previously called 911 and said he had killed a woman though police couldn't find evidence to support his claim.
Scott attempted to bring Chavez down with a Taser but it was ineffective so he shot Chavez in the leg and torso.
Chavez was rushed to San Juan Regional Medical Center where he died, according to the original Farmington police press release.
The next officer-involved fatal shooting was three weeks later.
Hill shot and killed Daniel Rey, 33, on Jan.
Rey was holding a machete and charging at Hill when he was shot five times and died, police have said.
Both Scott and Hill were placed on paid administrative leave after the shootings and have since returned to work on restrictive duty. Scott is currently completing an out-of-town training program and Hill is training and recruiting.
Farmington Police Chief Kyle Westall said his decisions as to whether Scott and Hill return to active duty won't hinge on the grand jury outcome.
A grand jury hasn't convened in Farmington in more than 10 years. During past officer-involved shootings, prosecutors examined the evidence and then elected not to pursue criminal charges, O'Brien said.
If the grand jury is convened, prosecutors will present evidence to a 12-person jury during private hearings.
The jury then votes on whether or not to indict the target of the grand jury. Eight jurors have to agree in order to indict a person.
Unlike a preliminary hearing, which is the more common practice in San Juan County to determine whether a defendant will face charges in district court, defendants don't get an opportunity to present evidence or object to prosecutors.
"There is nothing about the recent cases that is causing the shift in policy in the event we do a grand jury," O'Brien said. "It should give the public an extra level of confidence that the review is not being done by an agency that works in law enforcement and works with the officers who are the subject of the investigation."
Farmington Police Lt. Taft Tracy said the department would welcome a grand jury because it can help maintain trust between the public and the police by allowing the public to review evidence and decide whether the shootings were justified.
The alternative to a grand jury is for an outside police agency to gather evidence and then for a district attorney to decide to prosecute or not.
"In the eyes of the public, police officers are police officers and we'll be in each other's corner. It's the thin blue line," Tracy said. "A grand jury is not a part of that."
A grand jury will also have the potential to bring an end to suspicion that follows an officer after he is involved in a shooting, Tracy said.
If the grand jury doesn't find there is enough evidence to indict the person, the matter can never be presented to a jury again.
Ryan Boetel may be reached at email@example.com; 564-4644. Follow Boetel on Twitter @rboetel.