Davis' testimony came as defense lawyers began their assault Monday on key government witnesses in the racketeering retrial of reputed Philadelphia mob boss Joseph Ligambi and his nephew George Borgesi.
At the top of their list stood Monacello, a former Borgesi soldier turned mouthy FBI cooperator who provided some of the most colorful testimony against his former colleagues over four days last month.
Monacello had told jurors that Ligambi and Borgesi oversaw a criminal network that controlled illegal gambling and loan-sharking across the region. Defense lawyers unleashed a host of witnesses primed to expose cracks in his testimony.
Davis, longtime driver for Anna C. Verna when she was City Council president, said he socialized three to four times a week with Monacello. When it came to Ligambi, Monacello rarely minced words, Davis said.
"I hate him with a passion. You don't know how much I hate him," Davis recalled his neighbor's saying.
Monacello also bragged about throwing around Borgesi's name without his knowledge "because he could get whatever he wanted," Davis testified.
"Louie thought he should be running the mob," Davis said.
But the relationship between the Council aide and the mob figure soured in 2011, soon after Monacello was arrested along with Borgesi, Ligambi, and other mob defendants.
Monacello asked Davis to retrieve a loaded revolver hidden in the floor of his home. Davis agreed, but immediately had second thoughts, he said.
He told jurors he eventually turned the firearm over to the mob figure's mother.
Prosecutors seized on that decision in cross-examination, challenging Davis on his failure to report the incident to police or his bosses at City Hall.
"Did you ever tell Anna Verna that you were hanging out and drinking with a vicious criminal who bragged about how he wanted to be the head of the Philadelphia mob?" asked Frank Labor, an assistant U.S. attorney.
Davis, who now works as an administrative services coordinator for Council, said no. He also denied using Verna's car to pick up Monacello after an earlier release from jail.
Despite persistent questioning, Davis gave no credence to allegations his testimony was prompted by lingering resentment from a lawsuit Monacello filed against Davis' wife last year in a fight over a dining room furniture set.
"You're still angry, aren't you?" Labor insisted.
Davis shot back: "You'd like to think so, wouldn't you?"