The Thin Blue Line Flag: What It Means, Where It Came From, and Why It Is Controversial

The thin blue line flag is a black-and-white American flag with a single blue stripe. To the people who fly it, the stripe stands for law enforcement, and the flag is a show of support for officers and a memorial to those killed in the line of duty. The phrase traces to a British infantry stand at Balaclava in 1854 and was adopted by American police leaders in the 1920s and 1950s; the flag dates to 2014, when a Michigan college student designed it and founded Thin Blue Line USA to sell it. It is legal to display in the United States, and the Flag Code, which some cite against it, is advisory with no penalty. It is also genuinely contested: the Los Angeles Police Department and London's Metropolitan Police have restricted it on duty; critics point to its presence at Charlottesville in 2017 and the January 6, 2021 Capitol attack, and police unions and families of fallen officers defend it as a memorial that extremists do not get to redefine. Both sides are below, with sources.

In this article

• What the flag looks like and what it is said to mean
• Where the phrase "thin blue line" came from
• Who created the flag, and when
• Why the thin blue line flag is controversial
• Is it legal to display?
• How to display it, on a pole and on a vehicle
• Thin blue line vs. thin red line
• Frequently asked questions

What the flag looks like and what it is said to mean

The design is the 13-stripe, 50-star American flag rendered in black and white, with one stripe, usually the one just below the star field, printed in blue. The U.S. Court of Appeals for the Third Circuit described it in 2025 as "a black and white American flag" in which "all of the horizontal stripes are black and white with the exception of one horizontal stripe that is blue" (Fraternal Order of Police Pennsylvania Lodge v. Township of Springfield, 3d Cir., January 28, 2025).

No government or standards body defines what the elements mean, so the meanings are whatever the people flying it say they are. The ones given most often: the blue stripe is police, pictured as a line between an orderly society and disorder; the black is a mourning color for officers killed in the line of duty, and some supporters also read the black above and below the stripe as the public on one side and crime on the other; the black-and-white stars and stripes mark it as a stylized tribute, not the national flag. The flag's creator keeps it short. "The flag has no association with racism, hatred, bigotry," Andrew Jacob told The Marshall Project in 2020. "It's a flag to show support for law enforcement, no politics involved."

Where the phrase "thin blue line" came from

The phrase is a color swap on the "thin red line," which has a date and a place. On October 25, 1854, at the Battle of Balaclava in the Crimean War, the 93rd (Highland) Regiment of Foot under Sir Colin Campbell met a Russian cavalry charge in a line two ranks deep instead of the usual square. William Howard Russell, The Times of London's correspondent, wrote that the Russians "dashed on towards that thin red streak tipped with steel." The "streak" was shortened by repetition until "the thin red line" became the regiment's nickname; the U.K.'s National Army Museum credits Russell with coining it.

According to The Marshall Project's history, the police version took hold in 1922, when New York police commissioner Richard Enright used it in a public relations effort while under criticism. The man who made it famous was Los Angeles Police Chief William H. Parker, who led the LAPD until his death in 1966, used "thin blue line" constantly in speeches, and in the 1950s made it the title of a short-lived television program about the LAPD. The Los Angeles Times and The Marshall Project both credit Parker with popularizing the term.

One more push came in 1988 with Errol Morris's documentary "The Thin Blue Line," added to the Library of Congress National Film Registry in 2001. The title was pointed rather than flattering: the film documented how law enforcement sent an innocent man to death row in Dallas. By the time a flag appeared, the phrase already carried both the solemn meaning and the skeptical one.

Who created the flag, and when

The black-and-white flag with the blue stripe was designed in 2014 by Andrew Jacob, then a college student in Michigan, who founded and runs Thin Blue Line USA, a retailer of pro-police flags and merchandise. That account comes from Jacob himself in a 2020 interview with The Marshall Project, a nonprofit newsroom covering criminal justice. Jacob said he had seen the thin blue line image on patches and stickers before 2014, but never on an actual flag; the blue line between two black bars on police vehicles predates his design. The company has officially disavowed the flag's use at the 2017 Charlottesville rally.

Three things then carried it across the country: the "Blue Lives Matter" movement that grew after the shooting deaths of officers in Brooklyn, Baton Rouge, and Dallas; memorials, especially after the July 2016 sniper ambush that killed Dallas officers, after which The Marshall Project reports the flag "became a common sight in yards and on bumper stickers" there; and vehicles, where the flag followed the older sticker onto bumpers, windows, tailgates, and roll cages. In the U.K., the equivalent is a badge sold by the charity Care of Police Survivors for the families of officers who die on duty, which is why the British debate (below) is about a badge rather than a flag.

Why the thin blue line flag is controversial

Nearly everyone agrees the blue stripe refers to police. The disagreement is about what the flag signals when flown, and whether a government agency should fly it. Here is the record on both sides, each claim attributed to the person who made it.

Departments and governments that have restricted it

None of these is a ban on private citizens. Each is an employer deciding what its own personnel and property display.

The LAPD order followed a public complaint about a flag over the front desk of the Rampart station, per the Los Angeles Times. The Met's written answer adds that the force understands the badge "is completely legitimate in support of fallen police officers."

What critics say

Where it has shown up. The Marshall Project reported that the flag flew at the August 2017 "Unite the Right" rally in Charlottesville, Virginia, "appearing next to Confederate flags." On January 6, 2021, it was carried into the attack on the U.S. Capitol. Washington, D.C. police officer Daniel Hodges testified to the House Select Committee on July 27, 2021: "To my perpetual confusion, I saw the thin blue line flag, the symbol of support for law enforcement, more than once, being carried by the terrorists as they ignored our commands and continued to assault us" (hearing transcript, govinfo.gov).

The "us versus them" argument. Michael White, a criminology professor at Arizona State University, told The Marshall Project he understands why officers see solidarity in it but worries about the message: "It fosters this 'us versus them' mentality. The police and community should work together, in order to produce safety." Judge Schwartz, dissenting in the Springfield case, put it in one sentence: "To others, it communicates a white supremacist message, which could erode public trust in the police."

The altered-flag argument. Some critics say the design violates the U.S. Flag Code, 4 U.S.C. 8(g): "The flag should never have placed upon it, nor on any part of it, nor attached to it any mark, insignia, letter, word, figure, design, picture, or drawing of any nature" (law.cornell.edu). On this reading, recoloring the stripes and adding a blue one is exactly the alteration the Code warns against.

What supporters say

Police unions. After Chief Moore's directive, the board of the Los Angeles Police Protective League said, "It is difficult to express the level of utter disgust and disappointment with Chief Moore's politically pandering directive," and posted of the flag, "We will display it proudly and will not let anyone distort the true meaning" (LAist). In London, Metropolitan Police Federation chairman Rick Prior said families of fallen officers "will be equally dismayed" and urged the Commissioner to reconsider (question to the Mayor of London, 2024). The Pennsylvania FOP lodge took Springfield Township to federal court and won.

Families and officers. The memorial meaning comes first. Dallas Police Sgt. Stephen Bishopp, who lost colleagues in the 2016 ambush, told The Marshall Project: "When I see that flag as a sticker on a car or flying in someone's yard, I know that there is someone there that knows what I'm going through."

The Flag Code counter-argument. Supporters answer 8(g) on two grounds. First, the Code has no teeth: the Congressional Research Service states that it sets no penalties and has no enforcement provisions, and that it "functions simply as a guide to be voluntarily followed by civilians and civilian groups" (CRS Report RL30243). Second, the Code governs the actual flag, which 4 U.S.C. 1 defines as "thirteen horizontal stripes, alternate red and white," with white stars "in a blue field" (law.cornell.edu). A black-and-white banner with a blue stripe is not that object. The American Legion, which helped draft the Code, says in its flag FAQ that the Code "generally applies only to real flags, not printed images or designs," and that the federal definition of the flag "does not include clothing, stylized designs, or digital images that resemble the flag." As of 2020, the Legion had taken no official position on the thin blue line flag itself.

Is it legal to display?

Yes, in the United States, for a private citizen, without qualification. The Flag Code is advisory: it says how the flag "should" be handled and contains no penalty, and the Congressional Research Service describes it as declaratory and advisory, with no penalties and no enforcement provisions. The separate criminal statute, 18 U.S.C. 700, which once punished anyone who "mutilates, defaces, physically defiles, burns, maintains on the floor or ground, or tramples upon any flag of the United States," was held unenforceable in United States v. Eichman (1990); if burning a real flag is protected expression, a printed stylized one is not going to be prosecuted either. The Third Circuit held in the Springfield case that displaying the flag is speech on "a matter of public concern"; the ruling is non-precedential, but it affirmed a permanent injunction against the township.

Legal and permitted on the job are different questions. A department or a township can set uniform and property rules for its own employees, and whether a rule survives a First Amendment challenge depends on the facts: Springfield lost because it showed no actual disruption and singled out one viewpoint. None of that touches what you put on your own truck.

How to display it: on a pole and on a vehicle

There is no official etiquette for the thin blue line flag, because the Flag Code is written for the actual flag. The convention among people who fly it is to treat it with the same respect while never letting it take the national flag's place. Drawn from 4 U.S.C. 7, that works out to:

• Never above or to the right of the U.S. flag. "No other flag or pennant should be placed above or, if on the same level, to the right of the flag of the United States" (7(c)). On one pole it flies below the Stars and Stripes; on separate poles it goes to the U.S. flag's left, the observer's right.
• Union uppermost and to the observer's left when hung on a wall or in a window, as 7(i) sets for the real flag.
• Do not substitute it for the U.S. flag. Flying it alone is legal; flying it in place of the national flag on a public building is what started several of the disputes above.

On a vehicle. The Code's only vehicle rule is that the flag "should not be draped over the hood, top, sides, or back of a vehicle" (7(b)); it says nothing about decals. The American Legion's guidance for U.S. flag decals is that the union should face forward, "as it would on a flag carried forward," which is why a passenger-side flag is printed in reverse. The same convention applies to thin blue line decals: stars face forward on both sides. The full explanation is in our article on reverse American flag decals; the rules for the actual flag are in American flag etiquette and the Flag Code.

Thin blue line vs. thin red line

The thin red line flag is the same black-and-white design, but with a red stripe. It honors firefighters and is flown at firehouses and by current and retired firefighters as a memorial to those killed in service. The two are easy to confuse at a distance, but they belong to different services, and the red-line flag has not been subject to the restrictions listed above. Other colors exist for other services; those are covered, with a full table, in our article on what the colored lines on the American flag mean.

Frequently asked questions

What does the thin blue line flag mean?

It is a black-and-white American flag with one blue stripe, flown to show support for law enforcement and as a memorial to officers killed in the line of duty. The blue stripe represents police as a line between order and disorder; the black is usually described as a mourning color. Critics argue the flag has also been carried by extremist groups and signals an "us versus them" view of policing.

What does "thin blue line" mean as a phrase?

It describes police as a thin line between society and chaos. It is a color swap on the "thin red line," the nickname for the 93rd Highlanders' stand against Russian cavalry at Balaclava in 1854, as reported by Times correspondent William Howard Russell. American police adopted the blue version in the 1920s, and LAPD Chief William H. Parker made it famous in the 1950s.

Is the thin blue line flag disrespectful?

That depends on who you ask. Critics say it alters the national flag, which the Flag Code advises against, and that it was flown at Charlottesville and during the January 6 Capitol attack. Supporters say the Code applies to the real flag, not a stylized design, and that the flag is a memorial. The American Legion, which helped write the Code, says it "generally applies only to real flags, not printed images or designs."

When was the Thin Blue Line flag created?

In 2014. Andrew Jacob, then a college student in Michigan, designed it and founded Thin Blue Line USA to sell it, according to his 2020 interview with The Marshall Project. The blue-line-between-black-bars sticker on police cars is older than the flag.

Has the thin blue line flag been banned?

Not for private citizens anywhere in the United States. Several government employers have restricted it for their own personnel and property, including the Los Angeles Police Department in January 2023 and London's Metropolitan Police in July 2023. One such ban, in Springfield Township, Pennsylvania, was struck down as a First Amendment violation in 2023, and the Third Circuit affirmed in January 2025.

Does the thin blue line flag violate the U.S. Flag Code?

The Code, at 4 U.S.C. 8(g), says the flag "should never have placed upon it" any "design, picture, or drawing of any nature," and some critics apply that to the blue stripe. The Code is advisory with no penalties, and the American Legion's position is that it applies to real flags rather than stylized designs. Either way, displaying it is legal.

Related reading on this site: What the colored lines on the American flag mean, American flag etiquette and the Flag Code, Understanding reverse American flag decals on Jeeps.