Reason reported back in 2012 on a wrong-door smash-and-flashbang SWAT raid on a home in Evansville, Indiana. As Calvin Thompson wrote then:

When Evansville, Indiana, police officers started receiving threats against their families, they acted fast. The police traced the threats to the IP address of the Milan family on East Powell Avenue. And on June 21, they sent in a SWAT team to put on an impressive show of force. Evansville police arrived at the the home of 18-year-old Stephanie Milan and her grandmother, smashing an already-open door and tossing a couple of flashbang grenades in the building…. After smashing the window and busting open the door, they throw in two flashbang grenades, and then barge into the building to do their thing… After the raid, police determined that the WiFi connection was unsecured, meaning that anyone could have borrowed the connection to post the threats. Well, mistakes happen.

The Milan family sued the department, and last week the 7th Circuit Court of Appeals decided that the police had no legal immunity for being sued by the Milans for their actions that day. [UPDATE: Adding this up top since this was read ambiguously by some readers, but this decision does not say the cops lost the civil suit. It is saying that their attempt to argue that "qualified immunity insulates them from liability" for being sued at all failed, and, as discussed below, the lawsuit can go on to trial.]

Might be helpful to watch the video before hearing about the Court's decision. Start around minute 3 for action, before then to hear how these dudes comport themselves as they get ready to do some reeeeeeal bad policing:

I think you'll find the reactions of both grandmother and teen girl to be remarkably calm and contained given the absurd and violent circumstances. (There is some possibly horrendous dialog around 5:30 where one officer says "here's a cat" and another a second or so later says "I'll kick it" but it could be that he is referring to a door to knock it open and not the cat.)

In a decision written by the often-interesting and sometimes-libertarian-leaning Richard Posner, Posner notes the sued police:

argue that qualified immunity insulates them from liability—that is, that there was no established legal principle that would have informed them that they were using excessive force.

Posner disagreed, since he notes the police already knew there was an unsecured network near the house, and that they saw before they raided the Milans' two doors down on his porch:

a man named Derrick Murray, whom they knew to have made threats against the police in the past—indeed he had been convicted of intimidating a police officer. At least two of the officers thought him the likeliest source of the threats. Prudence counseled delaying the search for a day or so to try to get a better understanding of the Milan household and of Murray's potential responsibility for the threats. Prudence went by the board.

Bizarre postscript regarding Murray, the guilty party, who, as Posner notes, "A day of investigating him would have nailed him, as we know because a day of investigating—the day after the violent search of the home—did nail him":

that no men were found in the house during the raid confirmed the police in their belief that Murray was responsible for the threats. It took them only a day to discover that it was indeed he who was responsible—he had used Mrs. Milan's open network to threaten the police. But rather than give him the SWAT-team treatment, the police politely requested that he come to police headquarters, which he did, where he was arrested without incident. (He was prosecuted for the threats, pleaded guilty, and was given a sixteen-month prison sentence.) The police department's kid-gloves treatment of Murray is in startling contrast to their flash- bang assault on Mrs. Milan's home.

One hopes they merely had learned a lesson, for at least that week, about the dangers of SWAT raids. Hopefully they learned that they can not only be dangerous and mistaken, but also unnecessary.

Getting to actually see what happened helped Posner declare another aspect of the cops' behavior out of line:

The handcuffing of the daughter, looking indeed much younger than her 18 years, is shown on the helmet video along with the rest of the search, and she is so small, frail, utterly harmless looking, and completely unresisting that the sight of her being led away in handcuffs is disturbing. All that the SWAT officer had to do was take her by the hand and lead her out of the house, which was rapidly filling with smoke from the flash bangs; there was no conceivable reason to handcuff her. From what we can observe on the videos, all the members of the SWAT team were white, Mrs. Milan and her daughter black; the broadcasting of the videotape cannot have helped race relations in Evansville.

Posner concludes that the doctrine of "qualified immunity" for police work does exist and could have covered them even with the use of the flash-bangs, even with the fact they came up with no crime and no criminals, but:

to repeat for emphasis, the police acted unreasonably and precipitately in flash banging the house without a minimally responsible investigation of the threats. The open network expanded the number of possible threateners and just one extra day of surveillance, coupled with a brief investigation of Murray…should have been sufficient to reassure the police that there were no dangerous men lurking in the house. Precipitate use of flash bangs to launch a search has troubled us before [in a previous case], leading us to declare that "the use of a flash bang grenade is reasonable only when there is a dangerous suspect and a dangerous entry point for the police, when the police have checked to see if innocent individuals are around before deploying the device, when the police have visually inspected the area where the device will be used and when the police carry a fire extinguisher."…. The police in this case flunked the test just quoted. True, they'd brought a fire extinguisher with them—but, as if in tribute to Mack Sennett's Keystone Kops, they left it in their armored SWAT vehicle.

Police did replace a broken door and window and a burnt rug.

The Evansville Courier-Press quotes the Milan's attorney Kyle Biesecker on the suit, which can now go forward to a jury trial: