The racist graffiti unsettled Rankines, who said the neighborhood and school officials in the mostly white town embraced them when they moved there five years ago.
"Whoever put it there wanted it to be seen," he said on Friday. "It was a surprise, a shock."
Maple Shade police spokesman Lt. Jeffrey Hoch said authorities are investigating the incident as a bias crime, but do not know "whether it was somebody with a deep-seated hatred or kids that don't know the gravity of what they've done."
Rankines said he hoped it was only the work of a misguided youngster. So did others.
"A kid would be more brazen to go up and do it by the mailbox. And it's in chalk - it's got to be a kid," said Eileen Saxer, who lives across the street.
Police Chief Gary Gubbei said the incident was atypical: "We don't experience anything like this in Maple Shade. We don't have hate crimes in Maple Shade."
Pressed to think of a similar incident, Hoch said that some years ago children spray-painted graffiti on stop signs and businesses on Main Street, but the vandalism was not racist, and detectives tracked them down and "made them scrub it down."
Saxer said she, too, was surprised.
"The sign says 'Friendly People,' " she said, referring to the town's motto, "Nice Town, Friendly People," on road signs noting the township line.
"I don't know why they would do anything like that," she said, adding of the Rankineses: "They're nice people, churchgoing people."
Rankines is an agent at Keller Williams Realty in Maple Shade. At church, he oversees a series of business workshops called Entrepreneurs for Christ. He's also an elder.
He said his family was drawn to Maple Shade because a friend grew up in town and she and her family still live there.
Rankines is a 1989 Camden High School graduate whose grandfather emigrated from Jamaica.
By Friday, according to Rankines, his family was growing weary of the unexpected spotlight. His 14-year-old daughter sent him a text message asking him when the awkward attention would stop.
His middle child, a 17-year-old Maple Shade High School junior, didn't want to discuss the incident. The elder son, a 19-year-old freshman studying film at Fairleigh Dickinson University in Teaneck, doesn't like the attention either.
His daughter, a Maple Shade freshman, did wonder who the culprit was, and asked why.
"This is someone acting really ignorant," he said to a reporter Friday, wrestling to come up with an answer. "I thought we'd be beyond this by now."
He said he was using the experience as a teaching moment for his children: "I just talked about the definition of those letters. It's not a conversation I'd had in the past."