Was it Self-Defense or Murder by Alleged Mobster?

A reputed low-level gangster on trial for killing a high-level mobster in a Bronx street brawl is expected to take the witness stand Monday.

Frank Santoro, 59, is on trial for the July 11, 2002, murder of Thomas Pennini, who authorities said was acting as a good Samaritan trying to break up a street fight involving three women - including Santoro's girlfriend.

Bronx Assistant District Attorney Dan McCarthy said Santoro was a man who settled grudges with a bad temper and gun. Santoro's lawyer says his client shot in self-defense because he thought Pennini had a gun.

Santoro's jury trial is being presided over by state Supreme Court Justice David Stadtmauer.

Pennini was gunned down outside a doctor's office in Pelham Bay after he tried to stop a fight that a woman and her daughter were having with Santoro's girlfriend, authorities said.

In the midst of the battle, the girlfriend called Santoro, known as a neighborhood bookmaker, loanshark and leg breaker, on her cell phone.

"Santoro walked up to [Pennini] and pistol-whipped him across the face with that .45-caliber, semiautomatic pistol so hard that bystanders on the street could hear it," said McCarthy during opening statements.

However, according to McCarthy, Pennini "didn't go down, he tried to grab for the gun."

He said Santoro shot Pennini in the stomach and the bullet went through his abdomen and hit every major blood vessel. McCarthy said Santoro "left Pennini dying on a sidewalk."

Authorities said the 6-foot, 280-pound Santoro jumped back into his Chevy Blazer and fled. He was captured nearly two weeks later after a tip from a Daily News reader.

Santoro's lawyer Jack Litman said there is no debate that Santoro shot Pennini, but the shooting was self-defense. He said his client shot "Pennini once in the abdomen" because he thought the shiny blade Pennini had in his hand was a knife. "But it turned out to be a pair of scissors," said Litman. "He acted instinctively to save his own life. Frank Santoro, before July 11, 2002, had never seen Thomas Pennini. "Never met him, never talked to him and didn't know what he looked like."

Authorities described Pennini, 54, a local businessman, as a high-level independent mobster who worked for the Luchese, Genovese, Bonanno and Gambino crime families. He was particularly close to the Gotti family after having served an eight-year prison term for heroin trafficking a decade ago.

Litman said Santoro called 911 when he found out that the women had gotten into an altercation. He said the shooting was a justifiable and noncriminal killing.

If convicted, Santoro faces 25 years to life in prison.

Thanks to Chrisena Coleman