Baltimore police on Reisterstown Road near Mondawmin Mall on April 27, 2015. (Drew Angerer/Getty Images)

After a Baltimore woman reported her rape to police, the prosecutor on the case shared his thoughts with an officer. “I am not excited about charging it,” the unnamed official wrote in an email. “This victim seems like a conniving little whore.”

“Lmao!” the officer wrote back. “I feel the same.”

The Justice Department unearthed the exchange in a sprawling Aug. 10 report on the Baltimore Police Department, which found rampant discrimination against black residents, a tendency to use excessive force and a rash of illegal arrests.

Toward the end of the 167 pages was another bombshell: Officers frequently dismissed or mishandled sexual assault complaints. They often neglected to interview suspects or send DNA evidence to laboratories. Between 2010 and 2014, authorities tested rape kits in just 15 percent of adult-victim sexual assault cases.

The Justice Department concluded that “gender bias” had infected investigations. “In their interviews with women reporting sexual assault,” investigators wrote, “BPD officers ask women questions such as ‘Why are you messing up that guy’s life?’ ”

Meanwhile, just 17 percent of sexual assault reports in 2015 ended with an arrest. More than half of the reports made to the department languished as open cases.

“This data suggests that BPD is keeping the majority of its rape cases in an ‘open’ status, thus drastically reducing the rate of its rape cases closed as ‘unfounded,’ ” the authors wrote, “and creating the illusion of having made meaningful reforms to its procedures for identifying and classifying sexual assault.”

The DOJ investigation offers an extraordinary glimpse into a city police force’s inner workings. Investigators launched the probe after the 2015 death of Freddie Gray, a 25-year-old black man who sustained fatal injuries in the back of a police van.

But Baltimore’s isn’t the only force with race and gender problems. Last year, Attorney General Loretta E. Lynch announced that she’d heard about similar unseemly behavior from officers and prosecutors nationwide.

Authorities sometimes make snap judgment about women who report sexual assaults, she said at a White House event, where the DOJ released updated guidelines on how police should investigate rape. Officers judge complainants for getting drunk or wearing short skirts. They aren’t familiar with trauma’s impact on the brain, which can make victims seem strangely calm or unable to remember attacks in detail.

“These assumptions,” Lynch said at the time, “can send the case into a spiral of ineffectiveness, and the victim back into a spiral of despair and pain.”

Sexual assault remains prevalent in the United States. Nearly 1 in 5 women have reported rape, according to the latest DOJ statistics.

The Associated Press reported last year that assailants also operate from within police departments: One-thousand officers lost their badges from 2009 to 2014 for sexual assault and misconduct, according to their report. (Nine states declined to release data, so the number is a conservative estimate.)

Carol Tracy, executive director of the women’s law project, said last year that race is an important part of the sexual assault conversation. “This gender bias is exacerbated when racial bias is added to it,” Tracy said at the DOJ event. “Where bias is explicit, and it is explicit throughout this country, it has to be rooted out. ... Rape victims are profiled as liars, from campus to Cosby.”

Shanlon Wu, a former sex crimes prosecutor and partner at Wu, Grohovsky and Whipple in D.C., said all police departments should work to quash their acceptance of stereotypes. One baby step, he said: Officers should actively get to know people who don’t look like them. (Many police forces in the United Sttes are overwhelmingly white and male.)

“Police officers are just like the rest of us,” Wu said. “They can change biases through education and exposure.”

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