State police are investigating the death of a 21-year-old Gloversville man because of his involvement in an altercation two weeks before his death.

State Police Senior Investigator Karl Meybaum said Matthew Quackenbush, who died at Albany Medical Center Hospital on Saturday, was involved in an altercation with another person in the parking lot of the McDonald's in the town of Johnstown at about 5 a.m. Nov. 14.

Meybaum would not say if Quackenbush was injured in the altercation, but said he was transported to a hospital afterward. Fulton County District Attorney Louise Sira said several of Quackenbush's friends present during the quarrel noticed he was not acting well afterward and called medical officials.

Sira said Quackenbush and the other person involved in the fight, who she said was a man around Quackenbush's age, were having a disagreement that escalated to a brief physical encounter. She said the encounter was short and could not be characterized as a violent beating.

Meybaum said the investigation is complex because there are several factors involved, including Quackenbush's medical history and other incidents that may have taken place before the altercation. Sira said investigators are unsure if Quackenbush was involved in an accident or other fights before the Nov. 14 fight.

"We do know that [Quackenbush's] death and injuries seemed inconsistent with the argument that occurred [Nov.14]," she said.

The investigation is expected to be finished within a week, Meybaum said. He said those involved, including the other person in the altercation, have been cooperative. He said his office and investigators have been keeping Sira abreast of the situation.

Meybaum declined to say if he anticipated any charges being filed. He said that decision would be left up to Sira.

Sira said it is too early to say if any criminal charges will be filed. She said, as of now, it is unclear if a crime even took place.

"This is a preliminary investigation," she said. "It's too soon to characterize it in any way other than to say it is a death investigation."

Quackenbush's grandmother Kimberly Bombard of Johnstown called him "Quack" and said family members were shocked when he died.

"It's something none of us expected. They said he had a strong heart," she said. "It was jaw-dropping."

Bombard said Quackenbush was in a coma before his death but had woken up several times. That gave the family hope, she said.

"I kept telling [his mother] that he was in the best of hands, [and his death] isn't going to happen," she said. "[His mother] never left his side. She was there for 11 or 12 days straight."

Bombard said her grandson suffered a severe blow to the back of his head. She said she is aware of an investigation but does not know the details.

"We're just waiting to see what will happen," she said. "I have an awful suspicion. Justice should be served."

Bombard said about 700 people attended Quackenbush's wake and several hundred were at the cemetery. She said he was a smart, polite and well-groomed young man who had a lot of friends and was well respected among his colleagues at the Walmart Distribution Center in Johnstown.

Quackenbush's grandfather Everett Quackenbush of Oppenheim agreed.

"He always liked to help," Quackenbush said of his grandson. "This is a young person, 21 years old, who has his whole life ahead of him and something like this happens."

Larry Raike, general manager of the Walmart Distribution Center, declined to comment except to confirm Quackenbush had been working there on weekends.

Raike said Quackenbush had worked at the facility for a little more than a year. He said a number of his colleagues and Walmart Distribution Center employees attended Quackenbush's funeral Wednesday.

"A lot of us were there," he said. "There were quite a few people at the funeral. He had a lot of friends."