Credit: WROC

WEBSTER, N.Y. (AP) -- Police don't yet know if there are other victims in the homes that burned near Rochester, N.Y. early today.

They say the fire was set by an ex-con in order to lure firefighters to his neighborhood -- and that when they arrived, he opened fire, killing two firefighters and wounding two others. He then took his own life.

Police say William Spengler had served more than 17 years in prison for beating his 92-year-old grandmother to death with a hammer in 1980, at the house next to where today's attack happened. He was paroled in 1998, and authorities say he had led a quiet life since then.

Seven homes ended up burning after Spengler set a car and a house on fire this morning. The gunman's sister, who lived with him, is unaccounted for.

The two wounded firefighters are in guarded condition at a hospital. Both are awake and alert and are expected to recover.

Authorities haven't yet determined what prompted the attack.