Throughout the 1990s, the Detroit Police Department's rape squad looked great, consistently reporting the nation's highest arrest rates, always at least double the national average.
Women's advocates are alarmed and say the phony numbers gave them a false sense of security.
Now, the city's shame-faced police department acknowledges that the statistics were wrong and its crime data are so seriously flawed that it is unclear how many suspects really were collared. But it insists that the statistics were not deliberately changed and misreported, as they have been in many other cities where police departments dismiss rape complaints and try to boost their image.
The errors appear to follow the pattern of erroneous statistics for homicide arrests that were so high that they skewed national crime statistics. The fact that the city's crime data were misleading was uncovered by an investigation undertaken by the local newspaper, the Detroit Free Press.
"It might have been a computer problem, with duplicate entries for the same arrest," said Deputy Chief Paula Bridges. She added that she was unable to determine for how many years the misreporting has occurred.
Sheilah Clay, executive director of Detroit's Neighborhood Service Organization, said the misinformation has serious ramifications for her group that provides counseling and referral services to victims of sexual assault, domestic abuse and other social problems.
"It gives the community a false sense of security when that may not be an accurate picture," said Clay. "It has ramifications on levels that people wouldn't even think of."
Detroit's troubles highlight a national problem of police departments' inaccuracy in crime reporting--which often influences how departments provide services to rape victims.
Nationwide, Police Reporting of Rape Has Proved to Be Highly Flawed
Increasingly, police reporting of rape nationwide has been proved to be highly flawed.
Criminologist Alfred Blumstein, of Pittsburgh's Carnegie Mellon University, says police data on rape are far less dependable than reporting for other crimes because police departments differ in determining how women's rape complaints are counted.
"I don't trust the numbers," said Blumstein. "There's so much discretion in reporting."
Without accurate police reporting, women's groups can't judge whether police are solving rapes. Philadelphia police for years hid hundreds of sexual assault complaints in an effort to make the city look safer than it really was. St. Paul recently announced that throughout the 1990s, it mistakenly inflated its statistics for solving rape cases.
Detroit's problems exploded last month after news reports that the city's homicide arrest figures were so seriously inflated that they skewed the FBI's data for the entire nation. Year after year, it had told the FBI that it arrested about five times as many suspects as it really charged in killings.
For example, the Detroit Police Department had told the FBI that for 1999 there were 415 murders and 1,152 arrests in the Motor City, or nearly three times as many arrests as there were murders. However, Michael Cox, a deputy chief prosecutor of Wayne County, Mich., said in an interview that only about 200 suspects really were arrested in Detroit each year for murder.
Another measure of Detroit's inaccuracies are the FBI's national crime statistics for murder arrests. In 1999, the latest year for which FBI statistics are available, police across the country reported 15,533 murders and arrested 14,790 suspects--nine arrests for every 10 murders.
Flawed Statistics: Three Times the National Rate for Murder Arrests
But at the rate Detroit was reporting arrests, it would have been collaring 27 suspects for every 10 murders. In other words, Detroit supposedly was arresting murder suspects at three times the national rate.