Tracy Lawrence was making coffee around 6 a.m. one day last June when he glanced out a window and, to his shock, saw two teenagers casing his yard in rural Jackson County.

Although it was nearly summer, they were dressed in stocking caps and heavy coats. One was near Lawrence's pickup truck; another near his garage.

Lawrence grabbed his .22-caliber rifle and stepped out on back porch.

"What the hell are you doing?" he yelled.

The two 18-year-olds took off. Lawrence ran after them and fired his gun five times. He told police he didn't mean to hurt them. But Hunter Lentz dropped dead with a gunshot wound to the head. Matthew McMillen was killed by a bullet that ripped through his back and tore his aorta.

The police investigation shows McMillen and Lentz committed a string of break-ins that night before ending up at Lawrence's Springport home around dawn. A broken lock on Lawrence's camper and crowbars found in the grass suggest Lawrence interrupted a burglary.

But Michigan law only allows use of deadly force when someone is physically threatened. Stopping a fleeing burglar doesn't count. Lawrence is now facing two counts of second-degree murder.

At a time when sales of firearms for self defense are soaring, crime and health statistics show many purchasers overestimate how much protection a gun provides and underestimate the risks of owning a gun.

There are no publicly available statistics on how many total guns are licensed in Michigan.

However, as of March 1, more than 600,000 Michigan residents had active concealed pistol licenses, which is about 8 percent of the state's adult population. An estimated 29 percent of Michigan households have at least one firearm, according to a 2013 survey.

Between December 2012 and the end of 215, FBI background checks for Michigan handgun purchases increased seven-fold, to 141,689. Polls show the desire for personal protection is driving those sales.

According to a 2014 Gallup poll, more than six in 10 Americans believe a gun in the home makes it safer - a perception that has nearly doubled since 2000.

It is a movement fueled by recent mass shootings, including San Bernadino and Orlando; by local headlines, especially in urban areas like Detroit where crime is rife; and by gun-right advocates who say a good guy with a gun is the best defense against a bad guy with a gun.

Michigan residents who carry a gun "aren't looking for a fight," said Genesee County Undersheriff Christopher Swanson. "They're ready for a fight."

But Michigan incidents of armed citizens stopping a crime are relatively rare, based on a MLive survey of law enforcement officials in Michigan's 15 most-populated counties. Most officials could not cite a single incident in their jurisdiction within the past 12 months.

Meanwhile, there are at least four distinct risks from having a gun in the home:

Legal liability, as illustrated by the Springport case.

Risk of an accidental shooting.

Risk of a gun being used against a family member, friend or acquaintance during an argument.

Increased risk of suicide

"Where's the evidence that a gun in the home makes you safer? The surveys of gun research show the opposite," said David Hemenway, a professor at the Harvard School of Public Health and director of the Harvard Injury Control Research Center.

That said, Hemenway isn't seeking a ban on guns, he says.

"We're going to have guns," he said. "We love guns. So the issue is harm reduction."

Public-health experts say that means changes in gun manufacturing: Creating child-proof guns, for instance, and guns that can be remotely disabled when they are stolen, using the same technology used on cell phones.

That means changes in the law, such as mandating use of gun safes and/or gun locks in households with children under 18 and perhaps requiring new gun owners to attend a safety class that also would brief them on the Michigan law regarding self-defense use of a firearm.

In addition, Hemenway and others say it means public-awareness campaigns so Michigan residents are more cognizant of the risks, and the need for measures such as gun locks and removing a gun from the home when a family member is suicidal.

Kathy Wyatt, an analyst for the Washtenaw County Sheriff's Office said the gun issue is often seen through a political lens, "when we really need a public health approach."

"It's an epidemic and it's killing our families," Wyatt said of gun violence. "We need to look at this in a dispassionate, data-driven way."

Value of self defense

A sign in a suburban Grand Rapids gun store reads: "Why carry a gun? A policeman is too heavy."

Michigan's crime rate has been trending downward for years. The state's violent crime rate in 2015 was the second-lowest since 1969, and the property crime rate was the lowest since 1962, according to FBI statistics.

But media attention around mass shootings, terrorist attacks and spikes in gun violence in some cities such as Chicago have led to a perception that crime is on the rise.

The desire to protect one's home and family "has lot to do with" why handgun sales are skyrocketing, said Rick Bruner, a firearms instructor at the store, Silver Bullet Firearms Indoor Range and Training Center in Wyoming.

"When someone is breaking into your house at 4 a.m., you can call the police," Bruner said. "But at best, it's going to take eight minutes for the police to get there. Think of all the things that can happen" before police arrive.

That sentiment is backed by Detroit Police Chief James Craig, who oversees a city with 19 percent of the state's population and two-third of Michigan's gun homicides. Detroit's violent crime rate -- homicide, rape, armed robbery and aggravated assaults -- is five times that of the state average.

An armed citizen may be the only person around to shoot back in the seconds it takes for a gunman to release carnage, Craig said.

"That's when I take a position about what impact a law-abiding, responsible, trained citizen could have on mitigating an effect. It could." Craig said.

Saginaw Police Chief Bob Ruth said he believes there's a deterrent effect when criminals worry their victims might be armed.

"One of these days, these people keep robbing people, they're going to run into a person legally carrying a gun and we won't need to go to court. They'll end it," Ruth said.

In one of the more dramatic instances of a gun owner stopping a crime, a CPL holder interrupted a bank robbery in September 2015 in Warren.

Rubin Kendrick, 60, pulled his concealed pistol in September 2015 while walking out of the bathroom of a Citizens Bank lobby as a bank robber pulled his gun while trying to escape.

"They're both pointing their guns and the good guy lights him up," Warren Police Commissioner Jere Green said.

Kendrick emptied his clip, sending stolen money blowing in the wind outside as the armed robber went down with non-fatal wounds.

"If you or your family were in danger and a weapon was involved, I think you'd certainly want the opportunity to respond," Green said. "We don't want to create a vigilante culture, but we know people have the right to defend themselves and others."

Self-defense with a gun unusual

Green said Kendrick's was "clearly a clean shoot." He was not charged with a crime and investigators determined he acted lawfully, Green said.

But the Warren situation was a rare event, law enforcement officials say.

Nationwide, less than 1 percent of U.S. crime victims use a gun in self-defense, according to the FBI's National Crime Victimization Survey.

Michigan has more than 400,000 crimes against persons or property a year, based on state police data. In 2016, there were 45 instances statewide in 2016 where people used a gun in self defense, according to the Gun Violence Archive, a website that tracks self-defense shootings from a variety of sources.

To help determine the instances of private citizens using guns to thwart criminals, MLive surveyed prosecutor's and sheriff's offices as well as the largest police department in Michigan's 15 most-populated counties.

Thirty-one officials responded, including at least one agency from each county. Among the findings:

Twenty officials said the cases are rare, or could not locate one in the past year;

Six would not speculate on the frequency;

Two said it doesn't happen often;

Three recalled at least one incident in the past year.

Swanson, the Genesee County undersheriff, describes himself as a huge supporter of "good guys with guns," but said it is rare for gun owners to stop a crime.

"There are very few instances when people have used their guns in a self-defense way," he said. "For the amount of people who have their (concealed pistol license), it's not as often as you'd think."

The circumstances have to be just right for such an instance to occur, which explains why "it happens at an incredibly low rate," said Lt. Dave Schnurstein of the Grand Rapids Police Department. "It's an outlier that it ever happens."

And when it does happen, the outcome can be less than ideal.

Alaina Gonville, a Detroit bouncer and waitress, was carrying a Glock when she was accosted by an armed robber outside a convenience store in August 2012.

"He said, 'Give me all you got,'" she said.

Then she heard shots from a nearby car. She suspects they were the robber's accomplices, who saw the gun on her hip.

Gonville fired her Glock 11 times.

"I think they saw a female, they saw pink lipstick," she said. "They didn't know that I would be ready. They didn't know my training. ...They just saw a victim-to-be and that wasn't me."

The robber fled, but Gonville's left arm was badly injured in the shootout. Today, after multiple surgeries and physical therapy, she has about 70 percent function in her hand, she said.

It's possible that openly carrying the Glock drew the gunfire, Gonville said. But it's also possible the Glock saved her life.

"It's like I had no choice," she said about pulling the trigger.

Unintended consequences

Gonville's experience underscores a point made by many in law enforcement: Self-defense use of a gun may stop a crime, but it also may result in unintended consequences.

Death or injury isn't the only risk. Victims can find the law turned against them.

In January, for instance, an employee at a Lansing convenience store pulled his handgun on two armed robbers.

As the robbers ran, the employee shot at them from the store doorway and a bullet struck a car pulling into the parking lot.

The employee ended up pleading guilty to reckless discharge of a firearm, a misdemeanor, according to the Ingham County Prosecutor's Office.

"There's a fine line that a lot of people don't understand" about self-defense use of a gun, said Robert Merritt, spokesman for the Lansing Police Department. "You have a right to protect yourself when your life is in jeopardy. But when someone turns around and runs away or otherwise disengages, you can't use deadly force. The law doesn't allow you to pursue someone when they retreat."

Jared Hopkins is a lawyer for Tracy Lawrence, the Springport man facing homicide charges after killing the two would-be burglars on his property.

The Lawrence case "is not necessarily about gun ownership or gun use. It's about fear," Hopkins said. "Mr. Lawrence is a person who feels remorse in his heart. He was scared for himself and his wife."

Lawrence's trial is scheduled to begin April 17. His attorneys are planning to argue that the teens were on a crime spree the morning they were shot and killed.

"It's important for the jury to know that at 6 a.m., (Lawrence) sees people he does not know outside his home committing felonies," said George Lyons, the other defense attorney in the case. "Their intent is crucial to Lawrence's defense."

Death by gun

For those in public health, the gun debate isn't about crime stats. It's about deaths rates.

On average, about 20 people die by gun each week in Michigan -- an average of 11 suicides and nine homicides, in addition to accidental deaths each year.

In Michigan, 79 percent of gun homicide victims between 2010 and 2014 were killed by a family member, friend or acquaintance, based on an MLive analysis of FBI statistics in cases where the relationship between the shooter and victim was recorded.

"People assume all this violence is over gang warfare and drugs, which is not the case at all," said Greg Mathis, a retired Wayne County district court judge and star of the syndicated courtroom show "Judge Mathis."

"It's primarily the result of people resolving conflict by using guns," he said. "Much of what we need to do is get guns off the street so people can go back to fist-fighting."

Michigan lawmakers have introduced 102 weapons bills since 2015, the majority involving guns. Eighteen have become law.

Rep. Tim Kelly, R-Saginaw Township, introduced one of the most recent bills in February that would expand the categories of people allowed to carry guns in weapons-free zones, to include certain individuals petitioning for a personal protection order.

Suicides and accidental shootings

Access to guns also pays a role in suicides: While firearms are involved in only about 6 percent of suicide attempts, they account for about half of suicide deaths because guns are easily the most lethal means of trying to kill oneself.

In Washtenaw County, the sheriff's department is pushing the importance of gun locks and gun safes to prevent accidental shootings from children getting ahold of guns, Wyatt said.

"Not one or the other - both," Wyatt said about gun locks and safes.

Another suggestion from the Washtenaw County's safe gun campaign: Get parents to question other parents about guns in a house where children are invited to play. "Initiate that conversation to make sure parents are keeping guns in a safe," Wyatt said.

Yet another way to reduce gun violence: Pass laws prohibiting individuals at a high risk of violence from purchasing and possessing firearms -- such as individuals convicted of violent misdemeanors, domestic abusers, and individuals convicted of two or more DUIs, said Adelyn Allchin, a public health analyst for the Coalition to Stop Gun Violence.

Additionally, she said, a Gun Violence Restraining Order is an effective new policy in states such as California and Washington. Under such an order, law enforcement and family members can petition a court to temporarily remove a firearm from an individual who is a danger to themselves or others and prevent the person from buying new firearms while the order is in effect.

Gun safety has become a focus for Wayne County Prosecutor Kym Worthy after 10 cases in a seven-month span in which children found unsecured guns and shot themselves or someone else.

Worthy would like legislation that would punish gun owners who don't properly secure their guns, and as well as mandatory training for anybody who purchases a gun - not just for people who get a concealed pistol license.

"I want to make sure you're practicing safe techniques," Worthy said. "It can be criminal when you don't."

MLive reporter Brad Devereaux contributed to this report.