An Arizona real estate agent hasn’t been seen or heard from in more than a week, and police are trying to determine the identity of a mystery client who met with the man before he disappeared.

Sidney Cranston Jr., 40, agreed to meet a potential buyer at a vacant home in Kingman June 16, his brother Chris said. A neighbor reported seeing Cranston at the home, but Cranston mysteriously vanished after the meeting.

The Mohave County Sheriff’s Office and Kingman Police Department are involved in the search for Cranston.

Chris Cranston fears his brother may have been harmed.

“I’m pretty certain my brother was too trusting of his fellow man,” Cranston said. “I’m pretty certain he thought he was getting in a car to go show a property, and then they did something horrible to him, and possibly just for the few dollars in his pocket.”

Sid Cranston left few details about his plans, investigators say. He said only that his client was going to pick him up, and that he’d return home later that evening, according to some of his friends.Jennifer Sochocki, Kingman Police public information officer, said the case is being handled as a criminal investigation. The mystery client’s identity is unknown, she said.

“Our investigators are looking at every piece of information,” Sochocki said.

Chris Cranston said he can’t imagine who would harm his brother, a former engineer and avid motorcyclist.

“There’s bad, evil people in the world,” Cranston said, “and I need all the good people to try to help.”

Cranston is described as 5-foot-9, 162 pounds, with brown hair, blue eyes, and a light growth of facial hair. A $500 reward is being offered for information leading to his whereabouts.