https://www.nytimes.com/2023/04/19/us/yarl-gillis-shooting-missouri-ny.html Adam Matthews, who lives next to Mr. Monahan and has known him for decades, said his neighbor could be aggressive and intimidating. “He was a difficult guy,” Mr. Matthews recalled, adding he was “known to have altercations with people.” He added that Mr. Monahan was “always concerned with trespassing” and that the wide opening of his driveway resembled a road to some drivers. At one point, he said, Mr. Monahan had draped a chain across the mouth of his driveway, though the chain was no longer there last weekend.