SYRACUSE — Federal authorities charged six men Thursday for their alleged roles in a robbery that led to the shooting death of Daniel P. Simonds.

Three of them are in custody — Brian J. Latulipe, 27, of 73 Reardon Road, Bombay, Alan R. Jacobs, 33, of 18 Laughing Road, Hogansburg, and Kaientanoron L. "Nolo" Swamp, 28, River Road, Snye, Quebec, assistant U.S. Attorney John M. Katko said.

The remaining suspects named in the federal indictment still at large are Derek Cook, 28, of 70 Indian Village Road, Hogansburg, Chad Edwards, 21, of 116 E. Third St., Cornwall, Ontario, and Anson Edwards, 23, of 118 E. Third St., Cornwall. Federal warrants have been issued for their arrests. Other persons of interest are being looked at but have not been named.

All six were charged with conspiring to engage in a Hobbs Act robbery involving Canadian-grown marijuana that had been at Mr. Simonds's home in the town of Stockholm, according to the U.S. attorney's office. If convicted, each man could face up to 20 years in federal prison.

The superseding indictment handed up Thursday accuses them and other unknown assailants of robbing Mr. Simonds of the marijuana and money at his home in mid-May and beating and shooting him before fleeing.

Mr. Simonds, 31, of 649 Porter Lynch Road, died May 13 at Fletcher Allen Health Care, Burlington, Vt., after suffering a gunshot wound to the lower back.

The shooting took place in the early morning during a struggle with at least three unidentified suspects, according to investigators at the time. The suspects are said to have fled the scene in two dark sport utility vehicles.

In the aftermath of the killing, investigators found 140 pounds of high-grade marijuana, $50,000 to $60,000 in cash and a Russian-made hunting rifle at the Simonds home.

"It is still an ongoing investigation," St. Lawrence County Sheriff Kevin M. Wells said. "It has been a manpower-intensive, time-consuming and very detail-oriented investigation. Our investigators and task force team members have followed hundreds of leads and worked in a collaborative and cooperative matter working toward a successful conclusion of this case."

St. Law-rence County District Attorney Nicole M. Duvé said Thursday that her office continues following "solid leads" to identify the other suspects. She declined to comment on what linked the group of men together or who allegedly pulled the trigger that killed Mr. Simonds.

As part of the ongoing war on drugs in the north country, Ms. Duvé was appointed a special U.S. attorney in October. This was the first case in which she used those powers.

"This has been a very long and intense investigation," Ms. Duvé said. "It has been made very successful through the efforts of several law enforcement agencies."

First Assistant Federal Public Defender Lisa A. Peebles, representing Latulipe, said last month that her client wasn't the gunman. Defense attorney H. Dana VanHee of Syracuse, representing Swamp, on Thursday also said that his client wasn't the triggerman.

Swamp was arraigned Thursday before U.S. Magistrate Judge David E. Peebles and remains jailed until a detention hearing Tuesday.

Jacobs will be represented by New York City attorney Stanley L. Cohen, according to federal court documents. Jacobs was already in federal custody because he reportedly violated a condition of his release from another case, which involved a large amount of marijuana, Mr. Katko said.

"It is good news, it gives us some peace of mind," said Mr. Simonds's wife, Jessica L. Simonds. She thanked everyone involved in the investigation. "It will never change what happened, but it's a big relief that someone is going to answer for what happened that night."

Ms. Simonds said her late husband, an electrician, had worked for a time for Jacobs on the St. Regis Mohawk Reservation.

Several federal, state and local law enforcement agencies have assisted in the investigation, including the state police major crimes unit and the federal Drug Enforcement Administration.

Anyone with information is asked to call the St. Lawrence County Sheriff's Department at 379-2096 or 379-2222 or e-mail investigation@stlawco.org.