For more than a decade, Jeffrey Babbitt traveled two or three times a week from his home in Sheepshead Bay, Brooklyn, to a comic book store called Forbidden Planet just below Union Square in Manhattan. There, he bought the latest copies of “X-Men” or “Doctor Who,” or sometimes just chatted up the employees, who over the years had become good friends.

For Mr. Babbitt, 62, who friends said was a retired train conductor, the store offered an escape into fantasy and a bit of a respite from home, where he cared for his 94-year-old mother, Lucille Babbitt.

“He was just a really, really, really sweet guy,” said Jeff Ayers, a manager at the store who has known Mr. Babbit for years. “One of our staff just had a baby and he was dying to see pictures.”

Mr. Babbitt was walking through Union Square near Forbidden Planet last Wednesday when he was punched in the face seemingly at random by an assailant who, the police said, declared his intention to “punch the first white man I see.”