Monroe County Sheriff's Office via Reuters

William Spengler spent 17 years in prison for murder.

Nine years after brutally slaying his 92-year-old grandmother with a hammer, the man who opened fire on volunteer firefighters on Christmas Eve in upstate New York told a parole board in 1989 that he was worried he might kill again if freed, according to court documents.

“If you were capable of it once, are you capable of it again?" William Spengler wondered out loud at an Oct. 3, 1989, parole hearing, according to state criminal records released by the New York Department of Corrections in the wake of Monday’s shooting. 

"There is no reason why it should have happened,” he told commission members. “It makes no sense whatsoever. You know, hindsight is a great thing but it does no good." 

That exchange, which occurred at one in a series of parole board hearings from 1989-’97, took on added significance in the aftermath of the Christmas Eve attack, in which authorities say the 62-year-old Spengler set his home in Webster, N.Y., afire and then shot volunteer firefighters who came to put it out. Two firefighters were killed and three others, including a police officer, were seriously injured. Spengler then killed himself as police closed in.

The documents offer little insight into Spengler’s mental state leading up to the Dec. 24 attack, except to demonstrate that he unable to comprehend why he killed the first time.

Spengler frequently quarreled with the parole board members during the hearings, disputing how many times he struck his grandmother with the hammer in the July 18, 1980, attack, for example

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He also blamed his grandmother for precipitating the attack by hitting him in the groin, and said he only had the hammer because he was preparing to board up a basement door to prevent his grandmother from going to the cellar.

The parole board unanimously denied Spengler’s release in 1989, and subsequent boards did the same for six years, through 1997, when members said that “the extreme serious nature of your crime, the brutal beating of a 92-year-old grandmother with a hammer continues to militate against discretionary release."

It is unclear what led to Spengler’s release the following year. After spending 18 years behind bars he was well within the sentencing guidelines – between 8 1/3 and 25 years. But authorities could have held him another seven years.  

The state Department of Corrections provided this statement in response to an inquiry by NBC News.

"The last time he appeared before the Board was 1997.  He was conditionally released in 1998 as matter of law and remained under community supervision until the end of his sentence in 2006."

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