(Newser) – The Maryland man who opened fire on firefighters Friday night, killing one and seriously injuring another, is a "gentle person" who thought criminals were breaking into his home, his sister says. In what the sister calls a "tragic horror story," her 61-year-old brother shot at Prince George's County firefighters who were trying to gain entry for a welfare check after receiving a call from the man's brother, who said he was diabetic and had blacked out recently. "We are so sorry about the firefighter and for the family," the sister tells the Washington Post. "We were praying so hard." The fire department says the firefighters began breaking into the home after announcing themselves and pounding on the door, receiving no answer, reports Reuters.

"The way we're looking at it now is it's a terrible, terrible tragedy for everybody involved," Prince George's County Fire Department chief spokesman Mark Brady says. The man was released without charge Saturday night after being questioned, ABC News reports. A spokesman for the state's attorney's office says an investigation will "determine what, if any, charges are appropriate." The fallen firefighter, 37-year-old John Ulmschneider, was married and had a 2-year-old daughter, for whom a YouCaring fund has been set up, reports NBC Washington. Brady describes the firefighter and paramedic as a "good old hard working country boy who loved his job." The wounded firefighter, 19-year-old Kevin Swain, was shot four times but is expected to survive. (Read more Maryland stories.)

