How long do cops hang onto evidence?

Answers to your questions about the news.
Aug. 27 2004 6:01 PM

How Long Do Cops Keep Evidence?

Five years? Forty years? Until the end of time?

Police investigators in Houston, looking into incompetence at the city's crime lab, have discovered 280 boxes of lost evidence, covering around 8,000 cases stretching all the way back to the late 1970s. How long do police departments usually hold onto evidence?

Anywhere from the closing of the case until the end of time. There are few state guidelines addressing the long-term storage of evidence, so decisions about how to handle the materials are usually left up to local prosecutors and police. Some departments are assiduous about destroying evidence, say, one year after a defendant has either been acquitted or sentenced; others hold onto evidence indefinitely, figuring that they're better safe than sorry. It is not unheard of, for example, for evidence storage facilities to warehouse boxes of drugs that are 40 years old, or biological detritus from murder cases solved during the Johnson administration. Evidence from open, or unsolved, cases is frequently kept around for that long, unless the investigating officer is diligent enough to see to the evidence's destruction once the statute of limitations has expired.


There are also departments that may have disposal policies in place, but lack the manpower to determine which evidence should be preserved, which should be destroyed, and which should be returned to its rightful owner. It's estimated that a case's worth of evidence takes an hour to log and mark for disposal, retention, or return; that means that the newly discovered Houston evidence would take one police officer four full years of research (40 hours a week, 50 weeks a year) to identify and clear.

The downside to quickly disposing of evidence, of course, is that critical items sometimes get sent to the incinerator too soon. But evidence that's kept for the long haul can tempt property clerks and other insiders into stealing valuables. Tales of sticky-fingered employees are legion: Recently, for example, several Memphis, Tenn., workers were charged with lifting $2 million worth of cocaine from an evidence storage room.

When evidence is ordered destroyed, the process is usually done through incineration with at least two people present. Guns are often melted down, while hard currency may be donated to a charitable fund. Items that belong to a victim are returned to their rightful owners, who may have just 90 days to come in and claim their property.

Despite the disparity in evidence retention approaches, police departments are becoming more and more careful about preserving DNA samples for the long term. At least 25 states now have statewide policies in place regarding how long evidence containing DNA should be retained. Whereas such evidence might have previously been destroyed once an incarcerated defendant's appeals were exhausted, it's now often kept for the duration of the sentence in case a post-conviction DNA test is ever requested.

Explainer thanks Joseph T. Latta of the International Association for Property and Evidence, and Blake Harrison of the National Conference of State Legislatures.



Meet the New Bosses

How the Republicans would run the Senate.

The Government Is Giving Millions of Dollars in Electric-Car Subsidies to the Wrong Drivers

Scotland Is Just the Beginning. Expect More Political Earthquakes in Europe.

Photos of the Crowds That Took Over NYC for the People’s Climate March

Friends Was the Last Purely Pleasurable Sitcom

The Eye

This Whimsical Driverless Car Imagines Transportation in 2059

Medical Examiner

Did America Get Fat by Drinking Diet Soda?  

A high-profile study points the finger at artificial sweeteners.

I Wrote a Novel Envisioning a Nigerian Space Program. Then I Learned Nigeria Actually Has One.

A Futurama Writer on How the Vietnam War Shaped the Series

  News & Politics
Sept. 21 2014 11:34 PM People’s Climate March in Photos Hundreds of thousands of marchers took to the streets of NYC in the largest climate rally in history.
Business Insider
Sept. 22 2014 9:39 AM Adrian Peterson Has a Terrible Contract, and Cutting Him Would Save the Vikings a Lot of Money
The Eye
Sept. 22 2014 9:12 AM What Is This Singaporean Road Sign Trying to Tell Us?
  Double X
The XX Factor
Sept. 19 2014 4:58 PM Steubenville Gets the Lifetime Treatment (And a Cheerleader Erupts Into Flames)
  Slate Plus
Sept. 22 2014 8:08 AM Slate Voice: “Why Is So Much Honey Clover Honey?” Mike Vuolo shares the story of your honey.
Sept. 21 2014 9:00 PM Attractive People Being Funny While Doing Amusing and Sometimes Romantic Things Don’t dismiss it. Friends was a truly great show.
Future Tense
Sept. 22 2014 7:47 AM Predicting the Future for the U.S. Government The strange but satisfying work of creating the National Intelligence Council’s Global Trends report.
  Health & Science
Bad Astronomy
Sept. 22 2014 5:30 AM MAVEN Arrives at Mars
Sports Nut
Sept. 18 2014 11:42 AM Grandmaster Clash One of the most amazing feats in chess history just happened, and no one noticed.