America's cops aren't solving as many murders - here are some theories about why

About one third of all murders in the US go unsolved, according to a segment Monday morning on NPR.

Today, the national "clearance rate" for murders, which means the case ends in an arrest, is 64.1%. Five decades ago, it was above 90%.

This statistic means that 200,000 murders have gone unsolved since 1960, NPR noted.

NPR identified some potential causes for the depressing decline:

• Standards for charging a suspect are higher now, maybe even too high, Vernon Gerberth, a retired "murder cop" for the NYPD told NPR.
• People distrust the police and are less willing to help with cases, he said. Since the 1980s, police have complained about a growing "no-snitch" culture, especially in minority communities.
• Many unsolved cases also happen in these communities, making the people who live there more distrustful of police and less willing to cooperate.
• The high crime rates in the '80s shifted the focus to preventing, instead of solving, crimes.
  
• Homicide investigations are expensive. Poor, minority communities, like Detroit, which has one of the highest murder rates in the country, usually can't afford to lower investigators' case loads.

Listen to the full segment on NPR »