To better answer the questions that come to mind after this comment I give you the following. From Police Say They Tried to Contact Nashville Bombing Suspect Anthony Warner After 2019 Warning:
Nashville police said Wednesday that they repeatedly tried to reach Anthony Warner, the deceased suspect in the city’s Christmas Day bombing, soon after being told in 2019 that he was making bombs inside an RV at his home.
Joel Siskovic, a spokesman for the FBI in Memphis, said Wednesday there was no allegation of a crime made at the time to the bureau or police.
“If we were going to take action like a search warrant, we would have had to have probable cause,” Mr. Siskovic said. “We weren’t even at the stage where a crime had been alleged.”
The person who told the police he was making the bombs was his girlfriend who told them this did so after the police were called to the home because she was making suicidal threats.That visit didn’t provide a solid enough basis to get a warrant:
The woman, who officers determined was in need of a psychological evaluation, identified herself as Mr. Warner’s girlfriend and warned police that her boyfriend “was building bombs in the RV trailer at his residence.”
Assuming all this is true, I have to give law enforcement a pass for not stopping the bomber much earlier.