Raw videos that show officers shooting and beating unarmed black people have stirred outrage and prompted disbelief. Captured by cellphones or police cameras, footage has spread through social media, shining a light on disturbing police encounters.

“A lot of white people are truly shocked by what these videos depict; I know very few African-Americans who are surprised,” said Paul D. Butler, a law professor at Georgetown University and a former prosecutor.

The videos have led to nationwide protests and federal investigations. And even as policy and attitudes on race shift after footage goes viral, some worry that the constant exposure can desensitize viewers or cause psychological trauma, especially among people of color.

“I know lots of others like myself feel that this is something that really impacts our community, and we have an obligation to see it and understand it and make comments about it,” said Monnica Williams, a psychology professor at the University of Connecticut who studies racism-related trauma. “But watching it is soul-numbing.”

These videos contain disturbing and graphic scenes of violence. We have compiled them here to provide a record of the raw footage that has sparked a national conversation about race and policing.

Danny Ray Thomas A dashboard camera video shows Deputy Cameron Brewer confronting Danny Ray Thomas, 34, who is fighting with another man at a Houston intersection. Deputy Brewer screams at Mr. Thomas to “get on the ground” before fatally shooting him out of the camera’s view. The deputy has been placed on administrative leave.

Harris County Sheriff’s Office

Stephon Clark A police body camera and helicopter video show two police officers fatally shooting Stephon Clark, 22, in his backyard. A police statement said that the officers believed Mr. Clark was pointing a firearm at them, though investigators found a cellphone, but no weapons, near his body. The officers were placed on administrative leave.

11-Year-Old Girl A police body camera video shows an 11-year-old girl being held at gunpoint and then handcuffed as she screamed. Chief David Rahinsky of the Grand Rapids Police Department said in a news conference that the episode was “inappropriate.”

Grand Rapids Police Department

Johnnie Jermaine Rush A police body camera video released on Feb. 28 shows two white police officers Tasering and beating Johnnie Jermaine Rush, whom they accused of jaywalking. While pinned to the ground, Mr. Rush, who is black, cried out repeatedly, “I can’t breathe!” One of the officers has resigned, and the police chief offered to do so as well.

Asheville Police Department

Richard Hubbard III A police dashcam video shows Richard Hubbard III, 25, being beaten during a traffic stop in the Cleveland suburb of Euclid, Ohio. Officer Michael Amiott can be seen repeatedly punching Mr. Hubbard, who is black, and hitting his head on the pavement.

Euclid Police Department

Demetrius Bryan Hollins Cellphone video shows Demetrius B. Hollins, 21, being kicked in the head and punched in the face by two officers during a traffic stop. The Gwinnett County Police Department later dismissed 89 cases involving the officers, Robert McDonald and Sgt. Michael F. Bongiovanni, who were fired and face criminal charges.

Black Lives Matter Greater Atlanta

Nania Cain Footage from a dashboard camera and a cellphone shows Nania Cain being thrown to the ground and repeatedly punched in the face by an officer who claims Mr. Cain had allegedly jaywalked. Mr. Cain, 24, was initially charged with resisting arrest, but was released the next morning. The Sacramento police officer was placed on paid administrative leave.

Naomi Montaie via Facebook, Sacramento Police Department

Dejuan Hall Dejuan Hall, 23, was chased and apprehended by a police officer who is seen punching Mr. Hall and striking him with an object. In a bystander video, people can be heard yelling, “Police brutality.” The Vallejo police officer then shouts back: “Shut up. Get back,” and brandishes his gun.

Laura Maldonado via Facebook

A Rolesville High School student Cellphone video shows a police officer slamming a 15-year-old female to the floor in effort to stop a fight involving three students. Officer Ruben De Los Santos was placed on paid administrative leave, and did not face criminal charges. He resigned in March.

@ahunnaaa_ via Twitter

Jacqueline Craig and her children Jacqueline Craig, 46, and her daughters, ages 15 and 19, were arrested after reporting to police that a neighbor had choked her 7-year-old son for littering. Bodycam video shows the responder, Officer William Martin, asking the mother, “Why don’t you teach your son not to litter?” Later, he aims a Taser toward the family and then handcuffs the women. Mr. Martin received a 10-day suspension for excessive force and continues to defend his actions.

YouTube video uploaded by Shaun King

Charles Kinsey Charles Kinsey, a behavioral therapist, was trying to help a young man who has autism when Mr. Kinsey was shot in the leg by a North Miami police officer. Jonathan Aledda, the officer, was fired for shooting the 47-year-old. His commander, Emile Hollant, is to be fired as well.

@toddtongen via Twitter

Carnell Snell Jr. Carnell Snell Jr., 18, was fatally shot by the police in a strip mall parking lot. Surveillance video shows Mr. Snell running into the parking lot while tucking what appeared to be a handgun into his pants. The video was released after two days of protests over the shooting.

Los Angeles Police Department

Keith Lamont Scott Keith Lamont Scott, 43, was fatally shot by the police at his apartment complex. The police were there to serve someone else with a warrant. Mr. Scott had parked his car in a visitor’s space, where he often waited for one of his children to return home on a bus. The video was captured by his wife on her cellphone.

Evan Grothjan/The New York Times

Terence Crutcher Terence Crutcher, 40, was fatally shot by a Tulsa police officer who was responding to reports of an abandoned vehicle in the road. Footage from the dashboard camera of a police car shows Mr. Crutcher walking toward a car with his hands raised before being Tasered and then shot.

The New York Times

Paul O’Neal Videos taken from police officers’ body and dashboard cameras show two officers firing their guns at a stolen car moments before the driver, Paul O’Neal, 18, crashed it into a police vehicle. Mr. O’Neal was shot and killed in the back as he fled the scene and ran behind a nearby house. Police officers could be seen gathering around Mr. O’Neal as he lay on the ground.

Chicago Police Dept.

Joseph Mann Dashboard camera audio suggests that police officers tried to hit Joseph Mann with their patrol car as he fled on foot. “I’m going to hit him,” one officer is heard saying. “Go for it,” another says. Officers then followed Mr. Mann on foot and fired 18 shots, 14 of which hit him.

Sacramento Police Department

Philando Castile Philando Castile, 32, was fatally shot during a traffic stop in a St. Paul suburb, the aftermath of which was captured in a grisly video recorded by the car’s front-seat passenger and streamed live as the man slumped against her. Her young daughter sat in the back seat. In June, a jury found the Minnesota police officer, Jeronimo Yanez, not guilty of all charges, including second-degree manslaughter. Dashboard camera video was released days later.

Minnesota Bureau of Criminal Apprehension, Diamond Reynolds

Alton Sterling A cellphone video shows a black man, Alton Sterling, 37, being tackled and then held to the ground by two white officers. Someone shouts, “He’s got a gun!” and one officer appears to hold a gun above Mr. Sterling’s chest. Multiple gunshots are heard while Mr. Sterling is pinned down. Mr. Sterling died at the scene.

Nola.com

South Carolina High School Student Videos, apparently shot by students in a high school classroom, show a white school police officer grabbing an African-American student by the neck, flipping her backward as she sat at her desk, then dragging and throwing her across the floor.

YouTube video uploaded by Reginald Seabrooks

James Blake James Blake, a retired tennis star who is biracial, was standing outside a Manhattan hotel when Officer James Frascatore threw him to the ground, mistaking him for a thief. Investigators studying the surveillance video concluded that the officer had used excessive force.

New York City Police Dept.

Christian Taylor Surveillance cameras at a car dealership showed what occurred just before a white rookie police officer shot and killed Christian Taylor, 19, an unarmed black college student and football player. Officer Brad Miller was fired for using poor judgment.

Classic Buick GMC

Samuel Dubose The body camera for Officer Ray Tensing, of the University of Cincinnati police, captured the moment when he shot Samuel Dubose, 43, during a traffic stop involving a missing front license plate. Officer Tensing, who is white, faced a jury twice on charges relating to the death of Mr. Dubose. Both times ended in a mistrial.

Hamilton County Prosecutor

Sandra Bland Dashboard camera video revealed that the white Texas State trooper who pulled over Sandra Bland, 28, threatened her with a stun gun as their encounter escalated, partly because of her apparent unwillingness to snuff out a cigarette. Ms. Bland, a black woman, was arrested and later found dead in a jail cell.

Texas Department of Public Safety

A Teenager and a Pool Party Cellphone video showed a white police officer, David Eric Casebolt, pointing a gun at teenagers in bathing suits and shoving a black girl’s face into the ground.

YouTube video uploaded by Brandon Brooks

Freddie Gray Freddie Gray, 25, suffered a spinal injury while in police custody. He died a week later. The six officers involved in his arrest, a mix of black and white, were charged with crimes that included murder and manslaughter.

YouTube video uploaded by The Attorney Depot

Walter L. Scott A bystander recorded a white officer, Michael T. Slager, shooting an unarmed black man, Walter L. Scott, 50, in the back as he ran away. The video showed Mr. Slager firing eight times then casually walking over to Mr. Scott, who was pronounced dead at the scene.

Video made available to The New York Times

Tamir Rice Surveillance video showed Officer Timothy Loehmann, who is white, hopping out of a police cruiser and immediately firing two shots at Tamir Rice, 12, killing him at close range. Before the shooting, Tamir, who was black, had been using a fake gun that looked strikingly like the real thing.

Northeast Ohio Media Group

Laquan McDonald A dashcam video shows Laquan McDonald, 17, running, then walking past police officers when he is struck by bullets. One of the officers, Jason Van Dyke, who is white, was charged with murder on Nov. 24, 2015. Mr. McDonald, who is black, was shot 16 times.

Chicago Police Dept.

Michael Brown A bystander’s video showed Michael Brown, 18, lying in the middle of the street after being shot and killed by a white officer named Darren Wilson. His body stayed in the street for hours. He was unarmed. Mr. Wilson was not indicted.

Ace Johnson via Facebook

Eric Garner Eric Garner, 43, died after police officers tried to arrest him for the illegal sale of cigarettes. He was wrestled to the ground and placed in a chokehold. A cellphone camera held by a friend recorded the struggle as Mr. Garner told the police multiple times, “I can’t breathe.”

Taisha Allen

At least two videos since 2013 depicting police shootings of Hispanic men have also raised difficult questions about whether the shootings were justified.

Antonio Zambrano-Montes A video shot by a bystander showed a Hispanic man, Antonio Zambrano-Montes, 35, running from three police officers after being accused of throwing rocks at cars and officers. His hands were in the air when the police fired. Two of the officers were white; one was Hispanic.

YouTube video uploaded by Dario Infante Zuniga

Ricardo Diaz-Zeferino Ricardo Diaz-Zeferino, 34, was trying to help his brother find his stolen bike. Dashboard camera videos (which the police in Los Angeles tried to keep secret) later showed that he was shot when he was mistaken for the thief and did not keep his hands still in the air as instructed. The three officers involved were not charged.

Gardena Police Department