The knock on the door came at ten minutes before ten on a Monday night in January, just as Al Michaud was thinking about going to bed. He started to get out of his chair to see who was there.

His visitors were way ahead of him. Three large young men he'd never seen before burst through the unlocked door into his living room. "I'll take care of him — you guys go that way," one of them said, gesturing toward the bedroom.

They must have had Michaud pegged as easy prey. He was a short, heavyset guy in his fifties, with bad legs and a bad back, living in a crime-infested neighborhood on the east side of Colorado Springs. And growing weed right there in his pad; around the apartment complex, it was common knowledge that Michaud was a medical marijuana caregiver and was cultivating several plants.

But the men had miscalculated. They didn't know that Michaud was never alone, not since two burglaries the previous summer. He had two constant companions.

Mr. Smith and Mr. Wesson.

Born in Maine and raised in New Hampshire, Michaud had grown up around firearms. An avid hunter, he'd once had occasion to use a deer rifle in a complicated, deadly altercation with a fellow member of the Granite State Riders motorcycle club. Guns and home protection had become even more important to him since he began managing the squat, barracks-like apartments in Colorado Springs in exchange for free rent.

The place wasn't safe. Last August, someone had come in through his window while he was out and made off with a handgun and a laptop computer. Michaud had a pretty good idea who the culprit was; he even showed the police the trampled trail from his window to another tenant's apartment, but they didn't seem too interested. Two days later, Michaud let his neighbors know he was going fishing the next day and would be gone most of the day.

He waited quietly in his apartment until late the next morning, when he heard someone remove the fan from his window, step onto his bed and then head for the living room. "That's when I stopped him and busted him in the face with a fifty-caliber muzzle-loader," Michaud says. "He was a big kid, over 200 pounds. Fourteen, fifteen years old. They put him in a juvenile jail. He was out a couple days later on home arrest or something."

Tenants were always coming to Michaud with complaints, so he often didn't bother to lock his door. "If they feel bad enough to come in here, shit, welcome in," he says. He figured that catching a burglar red-handed would put the community on notice that he wasn't anybody's pigeon.

But no one had given these three home invaders the message. The first one headed right toward him. "I had no idea what they were going to do," Michaud says.

He had no time to think about the situation. What he had was a Smith & Wesson .357 Magnum, resting on the chair cushion. He picked it up and shot the first man in the chest. He hit the second one in the leg. Then the third one was on him, fighting for the gun.

Michaud managed to shove the man away. The three invaders fled as neighbors, roused by the commotion, began calling 911. When police arrived, they found two wounded suspects lying in the street a block away. A third soon turned himself in. Police also arrested a woman they believed to be the getaway driver. All four face charges of robbery and conspiracy; according to an arrest affidavit, they had planned to take Michaud's marijuana and any money they could find.

It didn't take long for authorities to determine that there would be no charges for Michaud. Colorado's home-protection statute — better known as the "Make My Day" law, a reference to Clint Eastwood's avenging cop, Dirty Harry — allows anyone to use deadly force in his or her home when confronted with an uninvited intruder and a reasonable belief that said intruder "is committing or intends to commit a crime" against person or property. Under such circumstances, the home defender is immune from criminal prosecution or civil liability.

It's not clear if the men who charged into Michaud's apartment that night were armed; Michaud doesn't recall seeing any weapon other than his own, and he had no opportunity to frisk anyone. But that doesn't matter for the purposes of Make My Day. If the occupant reasonably believes that the intruder might use physical force, no matter how slight, then a response involving virtually any degree of physical force, right up to decapitation and immolation, is considered justified.

Like dozens of similar incidents across the state since the law was passed in 1985, Michaud's defense of his domicile will go into the books as another righteous shoot. Not all of the cases involve shootings, of course; in some, invaders have been repelled with knives, fists or handy household blunt objects. But more than any other measure, the Make My Day law has helped to shape Colorado's favorable approach to defensive gun use in the home, even as state lawmakers have sought to impose a battery of other restrictions on gun capacity and purchases in the wake of last summer's Aurora theater shootings.

When the law was first proposed by two Republican legislators, it met stiff resistance from an unusual covey of prosecutors and liberals. Some denounced it as a "license to kill" that would pitch Colorado back to the vigilante justice of its frontier days. Others predicted that it would be manipulated by "gun nuts" to settle domestic or neighborhood disputes without fear of prosecution.

Many of those fears haven't panned out. While the law has sometimes been invoked in an absurd way — as part of a self-defense claim in the shooting of a troublesome relative or a drug dealer peddling ersatz merchandise — such claims have rarely been successful in court. Supporters of the law say it's working as intended, sparing crime victims from the ordeal of prosecution and having some residual, albeit hard to quantify, benefits to public safety.

"Make My Day just takes care of an edge issue," says Dave Kopel, the Independence Institute research director who's been involved in a lawsuit seeking to clarify the state's recent ban on high-capacity magazines. "It's not like it was illegal to shoot burglars before. You might occasionally have district attorneys who exercise bad judgment in these situations, but I think most DAs were using their discretion properly. It didn't change much in practice."

Kopel notes that his late father, Jerry Kopel, was a vocal critic of Make My Day when he was in the state legislature. "But the effects have not been the parade of horribles that people were worried about," he adds.

"I think it's an effective law, and it's been clarified over the years," says Denver District Attorney Mitch Morrissey. "When it comes up, which is rarely, we don't have trouble determining whether charges are warranted or not."

In fact, the measure is so popular that in recent years lawmakers have proposed amending it to encompass the protection of businesses as well — a step that makes Morrissey and other prosecutors uneasy, since it could well expand the use of deadly force in a wide range of situations. Once considered controversial, Make My Day is pretty tame compared to the sanctioned mayhem arising from more freewheeling interpretations of self-defense that have come after it, such as Florida's "stand your ground" statute — currently the subject of national debate, thanks to the O.J.-sized media attention devoted to the George Zimmerman trial. But that could change if Colorado's law is extended to confrontations outside a person's residence.

Count Al Michaud as one of the law's biggest fans.

Police treated him well after the shootings, Michaud says. "They wanted to give me a medal because I helped do their job. I think the law's great. I think when something like this happens, they should give us money and parade us around town and say how great we did."

**********

What's known in legal circles as the "castle doctrine" — the idea that your home is your castle and you have an inviolable right to defend it — is deeply grounded in English common law. Yet the effort to pass a home-protection statute in Colorado at the height of the Reagan era touched off a surprising political firestorm. The law had an even rougher reception in the courts, thanks to a particularly nightmarish early test case.

Bill sponsor Vickie Armstrong, then a state representative from Grand Junction, says the idea for Make My Day arose out of town meetings with citizens who complained that the existing self-defense law was too vague or confusing. Some said the law put too much burden on the home defender to prove an imminent threat and to show that the amount of force used was "reasonable" under the circumstances.

"A lot of people were concerned about protecting themselves," Armstrong recalls. "Theoretically, you couldn't use any more force than the person who was in your home [did]. And people were concerned about getting sued."

In language similar to that of a 1984 measure passed in California, Armstrong's bill allowed the use of deadly force to defend against someone who has illegally entered your residence. "It was very narrowly drawn," notes Jim Brandon, the bill's co-sponsor in the state Senate. "It had to be in the house, not on the porch or in the yard."

Brandon and Armstrong regarded the measure as a modest clarification of the right to self-protection, not a radical expansion of that right. It wasn't nearly as drastic as laws other states would soon pass, authorizing deadly force to prevent an intruder from attempting entry or eliminating a "duty to retreat" before whipping out your gun. Nor was it as all-encompassing as the "stand your ground" laws that would okay terminating threats with extreme prejudice but without regard to location. Yet some Democrats in the Statehouse were appalled; they described the Armstrong-Brandon proposal as a "shoot-'em-in-the-back" bill that elevated property crimes to capital offenses, sanctioning summary execution of some kid out to swipe your TV.

Brandon countered that no citizen should be required to determine an intruder's motives or level of weaponry before acting. "A young lady shouldn't have to ask, 'Are you here for my life or my jewels?'" he says. "I got asked, 'Do you think a man's life is worth your television set?' My response was, 'The guy who wanted the television set was willing to gamble his life. Stay out, and you're still alive.'"

Prosecutors also spoke out against the bill, saying it robbed them of essential discretion in determining what constituted unreasonable force. The opposition was so fierce that the proposal would probably have ended up on the legislative scrap heap, if not for the divine intercession of a certain squinty-eyed San Francisco police inspector. In a moment of levity, Dave Wattenberg, the state Senate prankster, handed Brandon a poster of a cowboy sitting at a bar with a whiskey, saying, "Go ahead, make my day" — the much-quoted line from the 1983 Dirty Harry movie Sudden Impact. The moniker stuck, and the press began referring to Brandon's home-protection statute as the Make My Day law.

Brandon wasn't happy with the reference, but it increased the bill's visibility. It also seemed to embolden its supporters. With the specter of Harry Callahan looming over them, one lawmaker had no trouble declaring that "sometimes blowing away dirtballs is the reasonable thing to do," while another joked about setting an annual "bag limit" for burglars. And it quickly became apparent that public sentiment favored the bill.

"The bill was in trouble in committee in the House," Armstrong recalls. "We didn't have the votes to get it out. But then the press started covering the bill, and a legislator came to me and said, 'I'll never get elected if I don't vote for it.' The public liked it, and that really started changing votes."

As the measure gained momentum, Armstrong and Brandon made a point of consulting with district attorneys to defuse their objections. Their input actually made the law stronger — for example, widening the scope of what was meant by "unlawful entry," so that it could include strolling uninvited through an unlocked door. The bill sailed to passage and was signed into law by Governor Dick Lamm; its sponsors found themselves on national talk shows, answering questions about whether everybody in Colorado was gun-crazy.

The national coverage of Make My Day soon took an even nastier turn, spurred by one particularly grim case that seemed to embody critics' worst fears about the new law. One night in the spring of 1986, a long-simmering feud among neighbors on Pearl Court in Northglenn erupted into bloodshed — and headlines.

For months, a frequently unemployed delivery driver named David Guenther had been involved in a series of petty disputes with other residents of the block, about everything from kids messing with his rock garden to others' unkempt yards to noise and parking issues. Guenther had put a sign on his front door, declaring that "the owner of this property is armed and prepared to protect life, liberty and property from criminal attack," but his badass approach just seemed to trigger more taunting.

On the night it all went ballistic, three neighbors who'd been drinking beer at the home of Michael and Josslyn Volosin decided it would be fun to let the air out of the tires of Guenther's car. One of them loudly invited Guenther to come out and fight, calling him a "big pussy." Guenther apparently slept through the commotion. His wife Pam called the police, but by the time they arrived the men were gone, and she declined to file a complaint. Hearing the loud party down the block, the two officers stopped by the Volosins' place to urge them to keep things under control, then left.

Police would later gather conflicting stories about what happened next. Michael Volosin claimed he heard someone kicking his door, figured it was Guenther and went over to his house to complain. He got into a confrontation at the Guenthers' front door with Pam, who claimed that Volosin pulled her outside and started to beat her. They both fell into the bushes.

Pam called out to her husband for help. David Guenther emerged from the house with a .357 Magnum in his hand and fired four times. He would later tell police that he shot randomly in the dark, trying to scare people away, and couldn't really distinguish among the "shapes" around him. If so, he was randomly deadly. He hit Volosin in the wrist and the leg. He shot a man who was headed toward the melee, Robbie Wardell, in the abdomen. And the fourth bullet hit Josslyn Volosin in the chest as she was trying to separate Pam Guenther and her husband.

Wardell and Michael Volosin survived. Josslyn died in the street.

Three months later, Adams County District Judge Philip Roan shocked the neighbors by tossing the case against Guenther out of court, saying the Make My Day law made it impossible to charge him. "It is a license for homeowners to kill without the possibility of being held accountable," Roan declared. "The court finds the statute in question is the most ill-considered statute this court has ever seen.... I think it's ridiculous."

An outraged neighbor wrote a letter to Judge Roan, informing him that Guenther had "been involved in at least two other incidents with a gun in which charges were also dropped.... How many times does he get to threaten someone with a gun or how many more people does he have to shoot in order to be put away?"

Prosecutors immediately appealed Roan's ruling. The Colorado Supreme Court upheld the Make My Day law but decided that Roan had misapplied it in Guenther's case. The charges were reinstated, much to the relief of Jim Brandon, who says actions like Guenther's fall outside the scope of Make My Day: "He was out in the yard shooting people. The law doesn't cover that."

Guenther received the news stoically. He was no longer talking about random shots; instead, he told the Rocky Mountain News that he "did what I thought was right" and "eliminated everybody in the yard who shouldn't have been there." He made these remarks from an Adams County jail cell, where he was awaiting trial on another homicide charge — the murder of his wife, Pam, and the wounding of her male companion outside a Commerce City restaurant, ten months after the Volosin shooting.

Pam had obtained a restraining order against her husband in early 1987, claiming that he'd beaten and abused her. David subsequently forced his way into the house and held her hostage at gunpoint for several hours before surrendering to police. Incredibly, he was able to bond out of jail for a mere $10,000. Terrified, Pam fled with her two children to a safehouse. But Guenther caught up with her a week later and gunned her down in front of their children.

The slaying shocked domestic-violence crusaders, who argued that the delay in prosecuting Guenther for his previous rampage merely encouraged him to spin out of control. A jury eventually acquitted Guenther in the killing of Josslyn Volosin — not under Make My Day, but through a tortured interpretation of established self-defense law. He was not so fortunate with the jury in Pam's death. They found him guilty of first-degree murder, and the judge gave him forty years to life.

The Guenther case became the focus of a 1988 PBS Frontline documentary; it also received detailed attention in a 1990 study of the new law prepared by William Wilbanks, a Florida criminologist. Wilbanks was skeptical of the benefits of Make My Day. His review of the first 23 Colorado cases in which the law was invoked as a defense found that most of them involved domestic violence, feuds among friends and neighbors or disputes among drug dealers — not unknown intruders seeking to rob or assault a homeowner. In fact, in only three of the cases was the intruder a stranger to the home defender, and in all of those, the "intruders" were police officers.

"An examination of the 20 cases involving non-strangers suggests that the homeowners used force (sometimes deadly force) as much out of anger as self-defense," Wilbanks wrote. He urged several clarifications in the language of the bill — including a distinction between intruders making "uninvited entry" and peace officers acting within the scope of their duties — that were never adopted.

At the same time, Wilbanks acknowledged that the law might be having some positive impact. While there are too many variables involved to draw a simple line of cause and effect, the burglary rate in Colorado declined significantly during the first three years that Make My Day was on the books — a slight increase in 1986, then a 13 percent decline in 1987, followed by a 10 percent drop in 1988.

In Denver, where the uproar over the Guenther case was almost impossible to ignore, police were taking nearly a third fewer burglary reports at the end of that period than they had before the law existed.

**********

Over the past 28 years, prosecutors and judges across Colorado have sorted through hundreds of finely nuanced varieties of around-the-house bloodletting, seeking to determine if the actions involved comprise a legitimate Make My Day case. Along the way, the law's limits and its loopholes have come into sharper focus.

Since there are no restrictions on the degree of force a resident may use in defense of home and hearth, even if the interloper is no longer a threat, one defendant was deemed immune from prosecution after stabbing an intruder 32 times. As some DAs have interpreted the statute, the intruder doesn't always have to enter the domicile, either. In 2003 an Ault man wasn't charged after the shotgun slaying of an angry neighbor who was on his front porch, pounding on the door and accusing him of shooting his dog. The neighbor never entered the man's house and was shot through the door.

There's nothing in the law to prevent an alarmed homeowner from shooting an exiting burglar in the back, providing some portion of his thieving anatomy is still in the house. But "hot pursuit" into the mean streets isn't allowed. Rob Coleman found that out in 1994, when his next-door neighbor, state senator and gun-control advocate Pat Pascoe, ran to his house and complained that men were trying to break into her place. Dressed in pajamas, Coleman chased an eighteen-year-old homeless man down an alley and shot him in the spine, paralyzing him. A former San Diego police officer who claimed to be suffering from a head injury, Coleman ended up pleading guilty to first-degree assault.

Judges have struggled with the definition of "unlawful entry," but in 2010, the Colorado Court of Appeals decided that an intruder doesn't have to know he's breaking the law — or, for that matter, to have any evil intent whatsoever — in order to be fair game for Make My Day. In cases where the shooter and the victim have some prior history, that reasoning has left questions about whether some unwitting "intruders" have been lured to their doom.

In 1992, William Harland's brother-in-law complained that Harland shot him after he and another man had been invited to Harland's house to fix a leaky faucet. But the jury acquitted Harland, who claimed he was acting in self-defense in response to a break-in.

Mustafa Ujaama's Make My Day claim wasn't quite as successful; he invoked the law after carrying out what prosecutors described as a cold-blooded plan to execute his wife's lover in 2006. Using his wife's cell phone, Ujaama exchanged multiple text messages with the man, luring him to a supposed tryst. When the man showed up, armed only with condoms and Viagra, Ujaama shot him nine times, rolled up his body in a rug, stuffed it in the trunk of the man's car — then hollered Make My Day. The jury thought the whole business sounded a lot like first-degree murder.

David Henry Wood had no better luck with his claim of having killed a threatening intruder. The intruder happened to be a meth dealer who had been invited into Wood's apartment to consummate a bit of business. When Wood discovered that the meth was fake, he disinvited the victim and shot him. Guilty, manslaughter.

In many other home-defense cases, though, prosecutors have declined to file charges, having determined that the situation, however strange, met the conditions of Make My Day. Last year Boulder authorities cleared a couple after the shooting and wounding of Zoey Ripple, an intoxicated college student who'd wandered into their home in the middle of the night and ignored warnings to leave.

Weld County prosecutors decided not to pursue a murky case against Karen Cordova in 2011, after she'd defended her medical marijuana grow operation from two would-be robbers — even though she apparently didn't call 911. One of the suspects staggered home with a stab wound; another was found a day later on the edge of Cordova's property, dead from a gunshot wound.

More clear-cut, and more in line with the law's intent, was Darrell Kutchin's response to a break-in at his Denver home by three teens in 2010. Asleep in his basement, Kutchin heard the crash of his front door caving in, armed himself, and headed to the main floor. The intruders came running down the stairs from the upper floor; seventeen-year-old Marcus Duran reportedly aimed a loaded pistol at Kutchin.

Kutchin fired twice. Duran was killed; one of the pellets from the .410 buckshot fired from Kutchin's Taurus Judge hit him in the head.

"That was so clearly Make My Day," says Denver DA Morrissey. Investigators learned that the teens had planned to break into cars that night, he adds, but had upped their game to home invasion after Duran decided to bring a gun along.

"There's no doubt in my mind [that] if I wasn't in the presence of mind to defend myself, I wouldn't be here today," Kutchin told CBS4 reporter Brian Maass. Still, the overall deterrent effects of a Make My Day law have proven difficult to measure. Both Colorado and Oklahoma experienced dips in burglary rates following the passage of such laws, but no long-range studies of the impacts of the legislation have been conducted since the 1990 Wilbanks book.

Florida criminologist Gary Kleck, one of the country's leading authorities on the use of guns for self-protection, has compiled data for decades that suggests instances of defensive gun use outnumber gun crimes in the United States by a wide margin — as much as five to one. But even Kleck is skeptical of the extent to which any single piece of legislation can alter established patterns of gun use.

"People have almost no knowledge at all of criminal law and the criminal-justice system," he says, "and very little accurate notion of changes in the law. It would surprise me a great deal if there was a change in the frequency of defensive gun use because of the change in the law."

Kleck's research does indicate that criminals are far less likely to attempt to victimize someone if they suspect that person is armed — and that widespread gun ownership discourages burglars from entering occupied homes, a phenomenon prosecutors know well. "The last thing a professional burglar wants to do is run into somebody who's at home," Morrissey notes.

If Make My Day has helped reduce the number of confrontations between residents and criminals, that's a good thing, argues Kopel of the Independence Institute. "It might not change the burglary rate overall, but it might displace some burglaries, so the burglars are more careful to make sure nobody's home," he says. "But there's no handy data on that."

The possibility that some of those displaced burglars are targeting businesses instead has been one of the arguments advanced in recent years in support of extending the Make My Day protections to business owners, too. Congressman Cory Gardner first proposed a "Make My Day Better" bill when he was a state rep in 2007; it's been revived and rejected every year since.

Both Brandon and Armstrong say the law should be expanded. "If it applied to businesses, we'd have a substantial lowering of instances of crime against businesses," Brandon predicts.

Supporters of the move cite cases like that of Christakes Christou, the owner of the Funky Buddha Lounge, who originally faced a charge of attempted murder after shooting a man who'd broken into the bar after closing in 2006. The intruder pleaded guilty to trespassing; Christou pleaded guilty to tampering with evidence — he'd allegedly picked up a shell casing — and received a deferred sentence.

But Morrissey, who's twice testified against Make My Day Better bills, says he hasn't seen one yet that he could endorse. "The problem with the laws I saw was that they were all written too broadly," he says. "They would allow the shop owner to shoot the shoplifter. You have to write it so tightly to make sure that the fifteen-year-old kid stealing a Baby Ruth bar isn't blown across the 7-Eleven."

**********

Al Michaud has three locks on his door, motion detectors installed around his front and back windows, a video camera in constant use. A sign on his door informs his neighbors that THERE IS NOTHING IN HERE WORTH YOUR LIFE.

You might think that's enough to keep the riffraff out. Michaud doesn't. He sits with a shotgun beside him, a pistol under his arm. "I never leave my house," he says. "It's not a question of if they're going to come back again. It's a question of when."

Michaud knows the law, knows what actions Make My Day allows him to take in his own defense, and what he can't do. That's why he didn't pursue the three home invaders when they fled his apartment last January.

"I don't want to be like Dirty Harry," he says. "But I've always been kind of ready."

Preparedness has been a longtime habit. Twenty-one years ago, on a quiet street in Manchester, New Hampshire, Alfred W. "Junior" Michaud got into a hell of a brawl with Thomas "Crazy Savage" Alden. The two had been friends, neighbors and members of the same motorcycle club, but the relationship had gone sour. According to news accounts, Michaud pulled a hunting knife but dropped it in the struggle, then called for his wife to bring his rifle. He shot Alden in the chest, killing him.

Michaud spent ten months in jail awaiting trial. The prosecutor talked about Michaud's duty to retreat, questioned whether he was in fear for his life, and pointed out that Alden was unarmed. Witnesses gave conflicting testimony about whether a third man pointed a gun — or was it a stick? — at Michaud and taunted him as the battle raged. The jury favored acquittal 10-2 but was unable to reach a unanimous verdict. The case was dropped.

"That's what brought me to Colorado," Michaud says.

The police seem to take a long time to respond to 911 calls in Michaud's neighborhood. They still haven't arrested anyone for the first burglary he suffered last summer, even after Michaud evicted the prime suspect and found his laptop in the perp's apartment when he was cleaning the place. Even after other tenants told him the dude was trying to sell the gun he stole. Michaud's gun.

"To this day they still haven't arrested that guy," Michaud says. "They're all having doughnuts and coffee someplace. They're going to wait until the gun shows up in another home invasion and probably someone gets killed because they can't do their job."

No, Michaud doesn't feel any safer these days. There are still burglaries in the neighborhood. People are still getting hurt. The situation calls for constant vigilance — more so now, perhaps, than before the three men went ahead and made his day six months ago.

"They thought they were just gonna run in on me and beat me up and do whatever they were gonna do," he says. "They obviously didn't know who they were screwing with. And since it happened, just about everybody's armed over here."