On April 29, 1992, Los Angeles erupted in what would be six days of rioting after four police officers were acquitted of charges of assault and excessive force against Rodney King. Post opinion writer Jonathan Capehart argues that a straight line connects that day to Baltimore, April 29, 2015. (Tom LeGro/The Washington Post)

The unrest in Baltimore this week has left the city charred and grappling with the tough issues of civil rights, race relations and policing. What began as calm demonstrations protesting 25-year-old Freddie Gray’s death in police custody escalated into violent clashes. Police, faced with angry, brick-throwing crowds, now patrol the streets beside National Guard soldiers after Maryland Gov. Larry Hogan (R) declared a state of emergency.

As fires blazed Monday night, some people took advantage of the chaos by smashing glass, prying open doors and looting businesses.

It’s a recurring scene in modern history: As passions over heady issues flare, thieves swoop in and ravage store shelves. It happened the same way exactly 23 years ago — on April 29, 1992, in Los Angeles — when riots erupted after a jury acquitted a group of white police officers who were videotaped savagely beating a black man, Rodney King.

Other instances include looting in Baghdad after Saddam Hussein’s government was overthrown in 2003, in London in 2011 and in the past year, amid riots in Ferguson, Mo., when looters stole grocery items and hundreds of liquor bottles during unrest centered on a white police officer shooting and killing a young, unarmed black man. Protests in Ferguson this week, in the wake of the Baltimore tumult, led again to violence and more arrests for looting.

A woman looks at documents near the destroyed window of a check cashing bureau at the Western District in Baltimore on April 29, 2015. Riot police enforced a curfew into the early hours of Wednesday and called it a success, emptying streets scarred by a spasm of rioting and looting. (Andrew Caballero-Reynolds/AFP/Getty Images)

But why does looting happen?

In a 2011 interview with the British Guardian newspaper, criminologist John Pitts told the newspaper that it often comes down to income and unemployment among deprived youth.

“Much of this was opportunism, but in the middle of it there is a social question to be asked about young people with nothing to lose,” Pitts said.

The 2011 London riots were touched off by the death of Mark Duggan, a black man who was shot and killed by police during an operation aimed at stemming gun crime. Firearm ownership is tightly controlled in the United Kingdom. It’s a theme many in the U.S. can relate to with the recent spate of high-profile incidents involving black men and police officers.

Timothy Parsons, a former chief inspector with the city of London police, said in an interview with The Washington Post this week that an analysis of the arrests after the London riots showed the vast majority of the city’s looters in 2011 were prior criminals. He also noted that looting occurs when there is motive and opportunity, and that it doesn’t necessarily have any real connection to the underlying reason for the unrest.

“Some were prolific criminals with many convictions,” Parsons said. “Of the remainder, the make-up was mixed, but essentially opportunist offenders who acted spontaneously thinking that they wouldn’t get caught.”

University of Leeds sociologist Paul Bagguley told The Post that looting often comes amid havoc on the streets, when police are likely to be distracted by violence.

“During riots, the normal rules of behavior are suspended — participants often describe a sense of freedom — so that normal respect for private property is suspended,” Bagguley said. “In addition, contemporary societies are consumer societies where one’s status and participation in society is defined by consumer goods, hence those excluded from consumption — the poor — are during riot conditions able to obtain valued items.”

Bagguley also noted that looters tend to target specific stores during the chaos.

“There is often evidence of rioters defending valued local retailers,” Bagguley said. “Looters thus tend to discriminate between targets following a certain rationality — it is not as indiscriminate as it looks.”

Looting has a long history. In the 5th Century AD, The Vandals, a Germanic tribe, sacked Rome and in doing so, became the namesake of willful destruction, otherwise known as vandalism. War is often the venue for infamous looting, such as when in 1796, Napoleon invaded Italy and stole away with hundreds of artworks to France. “The Louvre of this time was largely built on the systematic looting of Western Europe, and Egypt, of which Napoleon had made himself master,” according to a 2009 article in the New York Review of Books. And there were the notorious thefts of artwork and valuables at the hands of Hitler’s Germany, now the subject of popular movies such as last year’s “The Monuments Men.”

In some more modern cases, looting has occurred after riots sparked by sports fans, who take to the streets after a particularly grueling loss or joyous victory. Overwhelmed by a game’s outcome, passionate fans — often inebriated — have been known to flip cars, burn furniture and engage in brawls. With police attention on the fighters, looters can make away with goods from vulnerable stores.

Many notable U.S. riots in the modern era that ultimately led to looting have centered on contentious civil rights issues. Here are nine high-profile examples of looting in the United States and beyond:

1968: The death of Martin Luther King Jr. sparked unrest across the country. In the District, the city burned for three days. Countless shops were looted, including a liquor store across the street from Ben’s Chili Bowl on U St. in Northwest. Owner Ben Ali told the Washingtonian in 2008 that youths came into his restaurant seeking to pay for half-smokes with bottles of Courvoisier.

1992: The Rodney King riots in Los Angeles spread throughout the city during a period of escalated racial tension, and people across the country watched it play out on television. Shop owners stood guard with firearms to protect their businesses.

2002: The University of Maryland won its first national basketball championship and students celebrated in the streets by burning couches and anything else they could find. One bicycle shop incurred $35,000 in damage and lost more than 30 bikes.

2003: The U.S. invasion into Iraq led Hussein’s government to crumble, and the country dissolved into lawlessness. The National Museum of Iraq in Baghdad lost scores of precious artifacts dating back to Babylonia and Sumer.

2005: Hurricane Katrina made landfall in New Orleans. News organizations ran images of chilling messages spray-painted on plywood boards warning: “Looters will be shot.”

2011: After Duggan’s death, riots broke out across Great Britain. Youths ransacked London, often targeting brand-name stores seeking fashion goods. Police and authorities blamed social media platforms for fueling the attacks.

2011: The National Hockey League’s Vancouver Canucks lost in the 7th game of the Stanley Cup finals to the Boston Bruins. A Sears store was among a number of businesses looted during the riots. The Canadian city’s mayor described the perpetrators as “hooligans.”

2014: Storefronts along West Florissant Ave. in Ferguson, Mo., were destroyed in early August, after a police officer shot and killed 18-year-old Michael Brown, who was unarmed, sparking protests and violence. One tire shop had $150,000 in damage, according to the St. Louis Post-Dispatch. After the riots, some shops had sales drop 75 percent, according to the Post-Dispatch.

2015: A Baltimore CVS pharmacy was torched after looters stole prescription drugs, and other businesses were broken into as looters looked for valuables. Firefighters were pelted by stones as they worked to douse the flames this week. On Tuesday, a sign posted outside read: “THIS PROPERTY CONDEMNED.”

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