The former University of Cincinnati police officer charged with murder and manslaughter for shooting a driver during a traffic stop pleaded not guilty Thursday, and his attorney indicated that he would argue his client acted in self-defense.

In his first court appearance since his arrest Wednesday, Raymond Tensing, 25, spoke only to tell the judge he understood the charges against him, which carry the possibility of life in prison. Judge Megan E. Shanahan set Tensing’s bail at $1 million, prompting loud applause from the courtroom gallery. Later in the day, Tensing posted bond, and he is free pending trial.

“He was in fear of his life at the time this happened,” Stew Matthews, Tensing’s attorney, told reporters after the arraignment.

Tensing’s indictment for killing Samuel DuBose, 43, was unusual. Police officers are rarely charged for fatally shooting people while on duty. More than 550 people have been shot and killed by officers this year, according to a Washington Post database, and Tensing is the fourth officer to face charges.

Three of these officers were charged for shooting people during or after traffic stops, which can be tense encounters for police and drivers alike. Traffic stops are the most common reason for interactions between police and civilians, according to Justice Department data.

On July 19, University of Cincinnati police officer Raymond Tensing shot and killed Samuel Dubose during a traffic stop. This video shows excerpts from Tensing's body camera, as well as body cameras of two other officers at the scene during of the shooting. (Editor's note: Contains graphic images.) (The Washington Post)

On the night of July 19, Tensing pulled DuBose over for a missing front license plate. Video footage shows the officer asking repeatedly for a driver’s license before trying to open the car door.

Seconds later, the engine rumbled to life and Tensing’s gun appeared. DuBose, who was unarmed, was shot once in the head and pronounced dead at the scene.

Over the course of this year, interactions related to traffic stops have accounted for about 10 percent of the instances in which people were fatally shot by police, according to an analysis of data compiled by The Post.

Most of those fatally shot by police this year have been armed with a gun or knife or had another object believed to be a weapon, such as a toy gun. But among those shot and killed by police after a traffic stop, a far smaller proportion had a weapon than those fatally shot in other circumstances.

At least 62 people have been shot and killed by police across the United States within the past 30 days, according to Washington Post data.

The violation that prompted DuBose’s stop was described by Hamilton County Prosecutor ­Joseph Deters on Wednesday as a “a pretty chicken-crap stop.” But experts say those types of stops, often made when an officer suspects a more serious crime is being committed, are common and legal.

“It’s not an exaggeration to say that everybody involved in law enforcement and the criminal justice system understands that automobile stops are as often as not a pretext for dealing with other problems — mainly guns and drugs,” said Stephen Saltzburg, a criminal law professor at George Washington University.

Police officers are often accused of targeting motorists based on whether they are driving in high crime areas or fit a particular description. The popular saying “driving while black” is backed by federal statistics that show black motorists are more likely to be pulled over than white and Hispanic motorists.

Data analyzed by The Post also show that unarmed black and Hispanic motorists are disproportionately represented among those killed by police during traffic stops.

Police officers often justify deadly shootings by claiming a fear for their lives — a broad legal justification afforded to them by the courts. The Supreme Court has ruled that officers may shoot a fleeing, violent suspect who poses a public threat and use “reasonable” force if an officer believes a suspect poses an immediate threat.

So far this year, at least 16 police officers were shot and killed in the line of duty by suspects. Four of these officers were killed during traffic stops or in pursuit of a suspect, according to the National Law Enforcement Officers Memorial Fund.

The most recent was Sgt. Scott Lunger of the Hayward, Calif., police force, who was killed last week by a driver he had pulled over in the San Francisco Bay area. Authorities arrested the suspected shooter, Mark Anthony Estrada, 21, and he has been charged with murder.

In some cases, the vehicle itself has been deemed a weapon. In nearly three dozen cases this year, police who have fatally shot a driver or passenger have said the vehicle was being used to threaten or harm them.

Officers in Denver, for example, said they killed 17-year-old Jessica Hernandez in January because she was driving a stolen car toward one of them. A prosecutor later cleared the officers in the shooting, saying they were legally justified if they believed they were in “imminent danger.”

In the Cincinnati case, a police report filed by a fellow officer stated that Tensing said he fired his gun because he was being dragged by DuBose’s Honda Accord. But in footage from a body camera Tensing was wearing, he appeared to thrust his gun into the car after DuBose had started the engine but while the car was standing still.

“The argument that sometimes gets made is the car itself is sometimes a deadly weapon,” said David A. Harris, a law professor at the University of Pittsburgh and an expert in police use of force. “Well, he’s standing next to the car. . . . How does the car threaten his life if it’s going to go forward? Cars also go backwards, but I haven’t seen a car yet that goes directly sideways.”

Tensing was fired from his university police post following his indictment Wednesday. Thursday afternoon, the school placed two other campus police officers on paid administrative leave because of an internal investigation, said Michele Ralston, a spokeswoman for the school.

The two officers — Phillip Kidd and David Lindenschmidt — were mentioned in the university police report filled out by Eric Weibel, a third officer. Kidd is described as saying that he saw DuBose’s car drag Tensing, while Weibel wrote that it was not clear how much Lindenschmidt saw.

Earlier this month, an incident in Texas increased national scrutiny on the issue of the rights of motorists in interactions with police. Sandra Bland, a 28-year-old African American woman, was stopped by a state trooper in Waller County for not signaling a lane change. She was later arrested after the interaction became combative. Bland was found dead in a county jail three days later. Jail officials said she hanged herself.

Video footage of the stop released by authorities showed that the altercation escalated after Bland refused to put out her cigarette.

“These kind of incidents have been happening forever,” said Jason Williamson, staff attorney for the American Civil Liberties Union’s Criminal Law Reform Project. “But now that they’re being recorded and people are seeing how graphic they are, that has had a profound affect on the public, on law enforcement and policymakers.”

Experts say, however, that there is essentially only one critical right afforded to citizens during a traffic stop: the right to remain silent. Everything else is controlled by the officer, including the authority to order a motorist out of a vehicle.

“You don’t have to do anything other than give the officer your license, registration and proof of insurance,” Saltzburg said. “You don’t have to answer any questions.”

Steven Rich contributed to this report.