In recent weeks, the potential for harm has come to the fore after two deadly incidents in Washington, including the shooting rampage on Sept. 16 at the Washington Navy Yard that left 13 people dead including the gunman, who was shot and killed by police. Authorities said the man suffered from mental-health problems. Earlier this month, police shot and killed a Connecticut mother who tried to ram her car through a White House barrier. In that instance, critics including the woman's family have suggested police may have overreacted. Police in Washington have said mental-health issues were involved, and they are reviewing the encounter and the use of deadly force.
The Federal Bureau of Investigation keeps track of instances of "justifiable homicide," which it defines as "the killing of a felon by a law-enforcement officer in the line of duty," but it doesn't note which of those involve mental illness. While crime rates nationally have fallen almost every year since the late 1990s, justifiable homicides by police officers have risen, from 297 in 2000 to 410 in 2012.
Hidden within that category is what is known informally as "suicide by cop," when a person intentionally provokes an officer into using lethal force. Chuck Wexler, executive director of the Police Executive Research Forum, in Washington, D.C., which researches law-enforcement issues, said he believes this type of suicide is increasing in frequency.
Jill Harkavy-Friedman, senior director of research at the American Foundation for Suicide Prevention, said there aren't many studies of suicides that involve law-enforcement officers. A small number of studies, based on police records, have found in at least half the cases the victim had a known psychiatric history, and in at least a fifth the victim was undergoing treatment for mental illness.
Regular police training teaches officers at a crime scene to employ a force continuum, which starts with the fact of the officer's presence and, depending on how the subject responds, moves through verbal commands and hand controls and then to the use of a nonlethal device like a baton or Taser.
Generally speaking, nonlethal devices are considered appropriate options when more than one officer is present. As soon as the subject has a weapon, though, "options to deal with the situation rapidly decrease," said Lance LoRusso, an Atlanta attorney and author of "When Cops Kill."
In contrast, mental-health training tells officers to approach a subject who is thought to be mentally ill in a nonthreatening way and to use a conversational manner rather than barking commands, said Lou Reiter, a former deputy chief of the Los Angeles Police Department and a nationally known consultant.
About half the nation's population lives in places where officers don't receive training in dealing with the mentally ill, said Doris Fuller, executive director of the Treatment Advocacy Center.
Last year the Department of Health and Human Services reported that 44.7 million adults, or nearly a fifth of the adult population, experienced mental illness in the previous year, ranging from anxiety to extreme schizophrenia. That suggests an officer, on any given call, is reasonably likely to encounter a mentally ill person. Dispatchers try to give a heads-up if they suspect a call might involve someone with mental-health issues. Usually, though, it is just an officer and his or her instincts.
During a 2010 traffic stop in Portland, Ore., Officer Christopher Burley was trying to physically get Keaton Otis, 25, out of his car, after the young man had ignored police commands. Mr. Otis broke away, pulled a gun and shot Officer Burley twice. Mr. Burley's fellow officers responded by killing Mr. Otis. Later, they learned he suffered from a mood disorder marked by depression and paranoia.
Mr. Burley said it is easier to think that bad things happen only to bad people. Instead, he said, "it's a young guy who has been struggling with mental illness, and his family had been crying out for help." Mr. Burley is still an officer and now works with Mr. Otis's mother to raise awareness of the challenges faced by families of the mentally ill.
Boston Police Sgt. Detective Michael Talbot has flashbacks to the night, 21 years ago near Fenway Park, when he shot a mentally ill man who had ignored warnings and was advancing on him with a knife. "I remember praying the whole night saying, 'God, don't let him die,' " the officer said. He did die, though, setting off a civil lawsuit, a year of limited duty, an investigation and emotional turmoil. The Suffolk County prosecutor ruled the shooting was justified and the civil case was decided in the officer's favor. Still, if faced with the same scenario, he said, "I'd hesitate before I'd ever do it again."
Officer LaRosa's May 11, 2011, shift began routinely. He was driving his patrol car away from the office at 6:37 p.m. when he got the call that an SUV had crashed into a concrete pillar on Smiley Road.
Mr. Lane, 25, had been diagnosed six months earlier with bipolar disorder, which is characterized by extreme mood swings and sometimes-manic behavior. He had a breakdown and spent two weeks in a hospital, according to Dorothy Lane, his mother. Navigating the insurance and medical system and standing by their son became "the new normal," she said.
The day before Billy Lane's 26th birthday, the Lanes had dinner with their son at their home. He left, and at around 6:30 p.m. the couple was heading to a support-group meeting when they spotted his Jeep Grand Cherokee on the road. With no indication that he had seen them, the Lanes went on to their meeting.
Officer LaRosa, responding to the accident call, had barely turned on his siren when dispatch was back on the radio with an update: The driver was out of the vehicle. Seconds later another update came through: Witnesses said the driver was armed and threatening bystanders. A subsequent call reported the motorist had cut his throat.
Driving to the scene, Officer LaRosa wondered how an accident could have escalated so quickly. When he arrived, he saw bystanders backing away. As Officer LaRosa got out of his car, Mr. Lane, armed with a knife, started heading in his direction. Then, Mr. Lane turned and started to run, but, after a brief chase, he stopped and went toward Officer LaRosa again.
As Mr. Lane approached, the officer fired two shots and thought he missed. Mr. Lane was closing the distance between them with surprising speed. The officer fired twice more. Witnesses told police that Officer LaRosa had screamed repeatedly for Mr. Lane to stop, put down the knife and get on the ground, each time with more urgency.
Mr. Lane didn't say a word, Officer LaRosa said. The autopsy report said he probably couldn't talk because of the self-inflicted neck wound.
Ten minutes after he had arrived, Officer LaRosa was sitting alone in a patrol car while paramedics tended to the man he had just shot. "It was the loneliest feeling in the world," he recalled.
Over the next few hours, Chief Douglas Francis took the young officer's service pistol, a standard procedure, and talked to Mr. Lane's father and brother, who had arrived on the scene. Officer LaRosa called his parents to tell them he had been involved in an incident. He was placed on administrative leave pending the outcome of an investigation by outside law-enforcement officers and the Franklin County grand jury.
The grand jury asked questions like those raised by community members and news media. Why did the officer fire so many shots? Why didn't he use a Taser? Someone asked why he didn't shoot the knife out of Mr. Lane's hand.
The grand jury declined to press charges. Several months later, the department investigation concluded Officer LaRosa had conducted himself properly. He returned to duty in late May 2011 and was monitored for several months.
In 2011, the year of Mr. Lane's death, 8% of police incidents in Hilliard that involved use of nonlethal force, such as control holds, also involved mental illness, Chief Francis said. That rose to 26% in 2012.
Since the Lane shooting, Chief Francis has sent more officers to crisis-intervention training and acquired more Tasers. He doesn't think any of that would have made a difference in the Lane case, though.
When Mr. Lane didn't drop the knife and advanced on the officer, he crossed a threshold, the chief said. "If they have a gun or a knife, an officer only has a millisecond to debate this," he said.
Officer LaRosa replays the shooting in his mind: If faced with a similar situation, he would try to talk his way out—quickly. But given the same threat of violence, he thinks he probably would make the same call again.
"You go through the academy expecting Joe Bad Guy to bail out of a car and start shooting at us," he said. "They don't train us for Billy."
Officer LaRosa only recently overcame uncontrollable shaking that started after the shooting. "I found myself shaking on basic calls that would never bother me before," he said. "I never told anybody about it. I was afraid to tell people."
After the shooting, Officer LaRosa telephoned his brother and told him of his fears for him. Mr. LaRosa's father, Bob, called later to reiterate the message. With their father suffering from muscular dystrophy and their mother undergoing chemotherapy for breast cancer, the brothers have embarked on difficult conversations about their future.
"Shawn takes a lot of patience, and Tony never really had the patience to deal with it," said the officer's mother, Rusty. "But since this shooting, I think Tony understands more that a lot of what's happening to Shawn is not under his control."
Mr. Lane's parents haven't spoken to Officer LaRosa, but they said they don't blame him. "That was his job," Mrs. Lane said. "We read these stories in the paper just like anybody else, and we're so thankful our son didn't shoot a bunch of people."
The Lanes wrote a letter to the Hilliard police department, which said in part, "We are saddened by the circumstances Hilliard and Upper Arlington police encountered yesterday evening. We hold no ill feelings and extend our sympathy to the unfortunate officer forced to fire on Billy. We are convinced Billy achieved his desired outcome."
Sitting in the chief's office reading the letter, Officer LaRosa's eyes teared up. At one point he put a fist to his mouth as he thought of his brother: "All I can hear is my mom blaming herself…and the pain she has come through."