FORT APACHE INDIAN RESERVATION, Ariz. — A man in a dark shirt and hat emblazoned “POLICE” has raped 10 girls and a young woman after “arresting” them — a string of attacks that has made people on the reservation suspicious of even the real officers investigating the case. Residents of the tribal capital of Whiteriver are bolting their doors, walking in pairs, and demanding their children are inside by sundown.

“It’s unsettling,” Gwendena Real Bird, who has a 5-year-old daughter, said. “It makes you very uneasy. I just can’t fathom the trauma those girls experienced.”

The phony police officer has been attacking victims since March on a dusty trail that winds behind more than 100 homes in Whiteriver. He tells his victims they are under arrest, then handcuffs and rapes them. At first, nine of the 11 victims did not report that they had been attacked because they thought a police officer raped them. Eight came forward only when investigators canvassed the neighborhood recently to tell residents what was happening. Police found another victim after receiving an anonymous call.

“It has created an atmosphere of fear,” assistant agent in charge at the U.S. Bureau of Indian Affairs, Warren Youngman, said. “When we did our neighborhood canvassing, we had people afraid of our officers.”

Whiteriver, population 5,220, is the headquarters of the White Mountain Apache Tribe. It is the largest community on the Fort Apache Reservation, which covers more than 1.5 million acres in Arizona. The rapes have occurred between 10 p.m. and 2 a.m. on or near a 2-mile trail that Whiteriver residents use as a shortcut to travel among six subdivisions — One Step Over, Dark Shadows, Lifesavers, Bengay, Another World, and Chinatown. (As for how some of the communities got their names, One Step Over and Dark Shadows are near a cemetery; Lifesavers has brightly colored houses; and Bengay has a large number of senior citizens.)

Many of the homes are dilapidated, with sheets substituting for windows and walls cracked with age. Dogs roam the streets. The trail and the thick vegetation serve as a hiding place for teenagers who ditch school, drink, and do drugs. Teens commonly walk the trail by themselves at night, either on their way home from hanging out with friends or while visiting family members.

Investigators have described the rapist only as an American Indian of medium build, 20 to 40 years old. As far as investigators know, he last struck on September 6. The BIA, which is leading the investigation, has put together a 10-agent task force to investigate the crimes, drawing officers come from Arizona, Oklahoma, South Dakota, Nevada, and New Mexico. A $10,000 reward has been posted.