An illiterate parking attendant-turned-gravedigger for the mob yesterday gave damaging testimony that placed two alleged Mafia cops at the scene of two gruesome slayings.

Peter Franzone said that after one 1986 killing at a Brooklyn car lot – in which ex-cop defendants Louis Eppolito and Stephen Caracappa were on hand – he feared Eppolito so much that he kept quiet about the burial for 19 years.

“I was scared, because who is going to believe me if I mentioned a cop was involved?” Franzone said at the pair’s federal racketeering trial in Brooklyn court.

“I figure [Eppolito] would kill me or arrest me and put me in jail and have somebody else kill me.”

Franzone, a sixth-grade dropout, said that in the early 1970s, he got to know Eppolito’s cousin Frank Santora Jr. – a mob associate who allegedly helped serve as an intermediary between the NYPD detectives and higher-level gangsters.

Santora became acquainted with the garage keeper after getting tow services from him. They were so close that Santoro invited him to his home and introduced his cousin, Eppolito, to him.

The witness said that on Feb. 10, 1986, he watched as a mob hit involving Santora, Eppolito – and apparently Caracappa – took place at a single-car garage at his lot.

He said he was sitting in the lot’s attendant’s booth when Santora and a yarmulke-wearing mob associate known as Israel Greenwald walked into the lot with another man, who wore a trench coat with the collar pulled up.

“I saw his mustache, and I saw the pockmarks on his face,” he said, implying the man looked like Caracappa.

He testified that he later saw Caracappa at a Sweet 16 party for Santora’s daughter, and realized he was the man at the lot.

As they walked in, Eppolito parked nearby and watched the trio enter the garage. The three men were in there for about 20 minutes. Only two of them came out, driving off in Eppolito’s car.

Santora came back to the lot a short time later.

“He said he wants to show me something,” Franzone testified.

Santora”He opens the door a little way and says, ‘Go in there,’ ” Franzone said. “I turned the light on, and I saw a man slumped against the wall.”

It was Greenwald, shot and killed. Franzone pulled his Cadillac up. He took some shovels, a bag of lime and some cement out of the trunk.

“Frankie said I gotta help bury the body because I’m an accessory,” Franzone said.

Franzone said he took the short-handled spade and dug a hole in the garage, where the body remained until it was unearthed last year.

“I was afraid that he might [make me] dig it deep enough and just leave me in there,” he said.

SantoraHe said the Williamsburg man’s body folded into a near fetal position as it plopped into the hole. Santora covered the body with lime. Then they filled the hole and laid a coat of cement.

A year later, Franzone said, Santora killed another man at his parking lot, again with Eppolito on the scene keeping watch.

He that after Santoro and some other gangsters killed a victim named Pasquale Varialle, they made him lift the blanket-bound body into the trunk of a car.

He said he kept quiet, even after Santora died in the late 1980s, out of fear.

Also yesterday, prosecutors said they got a letter from jailed mob boss Anthony “Gaspipe” Casso concerning the case. They did not give details.

Casso is considered mentally unstable, but a witness said he paid the two cops for mob-connected work on several occasions..