those using the Breonna Taylor incident as an example. Yes, the cops were issued a 'no-knock warrant' but they banged on the Taylor door for several minutes, announced their presence and identified themselves as cops serving a warrant. They forced the door open after no-one responded to them banging on the door.
https://www.cnn.com/2020/07/23/us/breonna-taylor-police-shooting-invs/index.html
....Hours after Shaw signed the warrants, police began the operation, conducting near-simultaneous raids at the various locations.
Taylor's apartment, according to police, was considered a less volatile, "soft target." As such, police commanders decided in advance to have officers knock and announce their presence before entry. That decision was communicated in a pre-operational briefing, according to a source familiar with the details of the operation who requested anonymity due to the ongoing investigation.
Sometime after 12:30 a.m., Sgt. Jonathan Mattingly began pounding on the door. He later told investigators he believed Taylor was alone and he wanted to give her sufficient time to answer.
As officers waited for a response, a neighbor poked his head out to ask what was going on. One of the officers, Brett Hankison, extended his gun and told the neighbor to get back inside his apartment, Mattingly would later tell investigators.
"Brett was a little bit worked up," Mattingly said. "I remember looking at Brett, saying, 'Brett, relax. Brett, just relax. Relax."
When there was no answer after repeated knocks, Mattingly said, he announced he was a police officer there to serve a search warrant.
"Police. Come to the door," he said.
Another officer on the search team said he heard movement inside and thought someone was about to answer the door.
"We kept banging and announcing," Mattingly said, but still no one answered.
Eventually, a lieutenant at the scene gave the order to "go ahead and hit" the door with the battering ram, Mattingly said.
Taylor had been watching a movie in bed together with her boyfriend Kenneth Walker when she drifted off to sleep beside him. Walker told investigators he heard banging at the door after midnight and his first thought was that it was Glover. He said he knew Taylor had dated the accused drug dealer during their on-and-off seven-year relationship. He was concerned there might be trouble.
Taylor, who had awoken, shouted, "Who is it"?
Walker said there was no response.
He said he and Taylor scrambled to get dressed and that he grabbed his gun, which his attorney said he legally owns.
The pounding at the door continued, he said.
"She's yelling at the top of her lungs — and I am too at this point — who is it?" he recalled. "No answer. No response. No anything."
As they made their way down a hallway toward the front door, Walker said, the door flew off its hinges.
"So I just let off one shot," he said. "I still can't see who it is or anything.