The two surviving Webster volunteers, Joseph Hofstetter and Theodore Scardino, say they are "humbled and a bit overwhelmed" by well-wishes after the William Spengler shot and killed two of their colleagues in an ambush earlier this week.
Investigators are still looking into possible motives behind the shooting.
"Motive is always the burning question...I'm not sure we'll ever really know what was going through his mind," Webster Police Chief Gerald Pickering told USA Today.
Police discovered the body of 67-year-old Cheryl Spengler, sister of William Spengler Jr. on Wednesday in Spengler's home.
Police, who already voiced suspicion over Cheryl's death shortly after the shooting, say that the cause of death still remains unknown, but Spengler remains a prime suspect in the matter.
Pickering also said that a note by Spengler indicates that the Christmas Eve incident was planned well in advance.
"I still have to get ready to see how much of the neighborhood I can burn down and do what I like doing best: killing people," Spengler said in his two page note, as reported by USA Today.
Police have also revealed an array of weapons that were in Spengler's possession; among these were a Mossberg 12 gauge shotgun, a .38 caliber Smith & Wesson revolver and a .223 semi-automatic rifle - the same weapon used by Adam Lanza when he opened fired at the Sandy Hook Elementary school in Newtown, Connecticut, killing 20 children and six adults.
The 62-year-old Spengler spent 17-years in prison for beating his 92-year-old grandmother to death. He was paroled in 1998.
Spengler's attack claimed the lives of volunteer firefighters: Mike Chiapperini, 43, and Tomasz Kaczowka, 19.
Scardino, 48 and Hofstetter, 33 are reportedly in stable condition at Strong Memorial Hospital.
