BEVERLY, Mass. (WHDH) -- Several cars were found burned in a Beverly neighborhood and police are trying to find who is behind the arson attacks.

Investigators thought the first case was simply an accident. But after a fire started inside an elderly couple's garage, police knew someone started it.

Retired businessman Richard Broderick, 90, has lived in his home for more than half a century and can't understand why anyone would set his car on fire.

“I came down, opened the door, and flames were all over the place. Just slammed the door…called 911,” Richard Broderick said.

Had the fire spread to the house, his 91-year-old wife might have been trapped upstairs. A motorized chair is her only way out.

When someone set a fire in the Broderick’s garage three months ago, investigators thought it was accidental -- but two other suspicious fires in the neighborhood since made them realize they had an arsonist on their hands.

“Whether it’s children or elderly, it’s a scary thought,” said Dep. Chief Bill Walsh, Beverly Fire Department. “This person could be out there not thinking about the ramifications of his act.”

Neighbors can't understand how someone would target this 90-something couple not once, but twice.

Richard Broderick says he's too old to get angry.

“What good is it to get angry? There’s nothing I can do about it. I’d just like to know why somebody is dumb enough to do it,” Richard Broderick said.