Many paths possible in prosecution of man accused of slaying 10 at Tops

But there is no definitive answer yet on precisely what that process will look like.

Complete coverage: 10 killed, 3 wounded in mass shooting at Buffalo supermarket

Payton S. Gendron, 18, already faces a state charge of first-degree murder for the massacre at the Tops Markets on Jefferson Avenue.

Federal authorities have said they are investigating the mass killing "both as a hate crime and racially motivated violent extremism."

The victims: What we know about those killed, injured in Tops shooting

While New York State has no death penalty, the federal government does. A decision by federal prosecutors on whether to seek the death penalty is likely months away, according to veteran area defense attorneys.

Gendron can simultaneously face charges in both state and federal court, or one case can proceed before the other. Being charged in both state and federal courts would not violate the constitutional prohibition on "double jeopardy" because both levels of authority have jurisdiction at the same time, said Thomas J. Eoannou, a defense attorney who is not involved in representing Gendron.

"The legal process will be very involved," Eoannou said, even though the evidence "appears, at this point, to be overwhelming."

If convicted of first-degree murder in state court, the maximum sentence Gendron faces is life in prison with no possibility of parole.

Gendron, of Broome County, is scheduled to appear in Buffalo City Court on Thursday morning for a felony hearing, which is the next step in the legal process on the state charge.

Gendron's defense attorneys have withdrawn a request to have doctors review their client's mental competency, District Attorney John J. Flynn said Monday.

The move means the hearing on Thursday may proceed as scheduled. The hearing could not have been held unless the experts' examinations had been completed by then.

At Gendron's arraignment Saturday in City Court, defense attorney Brian Parker asked a judge to order a forensic examination of his client.

When asked Monday about the withdrawal, Parker declined comment.

Thursday's scheduled hearing still may not, in fact, take place, as the defense has the right to waive the hearing. After the hearing, or after it's waived, county prosecutors have 45 days to get a grand jury indictment.

Gendron currently faces a murder count that encompasses all 10 victims who were killed, and county prosecutors are still evaluating potential options for what he may be charged with, the district attorney said.

There are three "overarching areas" under which Gendron could be charged, Flynn said – murder, hate crime and domestic terrorism.

There is a criminal charge in New York that covers the latter two areas, known as "domestic act of terrorism motivated by hate." Anyone convicted of that charge faces an automatic sentence of life without parole, Flynn said.

Prosecutors may also decide to charge Gendron with 10 counts of second-degree murder, while applying what's known as a hate-crime enhancement, which stiffens the penalty if convicted.

For those victims who survived, Gendron could face attempted murder or assault charges, or both, Flynn said. Those could also be charged with hate crime or terrorism enhancements.

Then there are potential weapons charges.

"Those avenues are all being explored," Flynn said.

The charges Gendron will face and how his prosecution proceeds will depend on what investigators find in doing their work, said Terrence P. Flynn, former U.S. Attorney for the Western District of New York.

Other factors may also play a role, including if there are differences between jurisdictions on whether there is the possibility of parole hearings, the former federal prosecutor said.

It will be "fairly easy" for federal prosecutors to charge Gendron with a hate crime, based on the contents of his racist diatribe and what was written on the gun he used, defense attorney Paul J. Cambria Jr. said.

The firearm had markings, including a racial slur spelled out in white paint, as well as the number 14, which refers to a 14-word statement popular with white supremacists.

Some attorneys, including Eoannou and Joseph J. Terranova, said they expect the federal prosecution to happen first.

A recent case similar to what happened here, Eoannou said, is that of Dylann Roof, who killed nine people at an historically Black church in Charleston, S.C., in 2015.

Roof was first prosecuted federally and received the death penalty. Then he pleaded guilty in state court.

The decision on whether to seek the death penalty would come from U.S. Department of Justice officials in Washington, D.C., and a federal jury's decision to impose the death penalty would have to be unanimous, Eoannou said.

Gendron remains held without bail in the Erie County Holding Center.