For years, the hard-headed Irish-American gangster Frank Smith complained that he couldn’t catch a break — despite the valiant efforts of his loving mother and sister — as he served time in prison for a drug crime he didn’t commit.

In fact, the drug bust was the least of it. As Smith later admitted, he’d done much worse, participating in five separate killings, including the vicious mistaken-identity execution of the father of a federal prosecutor who had ticked off rulers of the Colombo family.

After copping to those hits — and providing some much needed testimony about one high-level wiseguy — Smith was sent off into the great American heartland with a new identity under the auspices of the Witness Protection Program. Ultimately, he was sentenced to one year, which he was allowed to serve at home with his family.

Even though Smith hasn’t done so well out there on his own, federal authorities appear to be sticking by their man. Today, no matter how much Smith messes up, the federal government seems ready, willing, and able to go to bat for the five-time killer.

Two months ago, Gang Land has learned, Smith was arrested for grand larceny after cops stopped a van loaded with stolen plasma televisions. Smith, a passenger in the vehicle, insisted he had no idea the televisions were stolen, sources said. Charges are still pending.

Normally, in the case of a protected witness like Smith, the feds would immediately alert the judge in the case, as Smith at the time of that arrest was serving five years’ probation for the killing of George Aronwald, whose son William was the man that Smith and two cronies set out to kill in March 1987.

Exactly where Smith was living at the time of the plasma TV bust is a secret, but it was obviously not too far from the Big Apple. According to knowledgeable sources, Smith was close enough to his old Brooklyn haunts to come back occasionally and hobnob with old buddies. He even found time to fall in love and get married, according to a source. Amazingly, after the feds — namely, the Brooklyn U.S. attorney’s office, the FBI, and the U.S. Marshal’s Service — all looked the other way after his first brush with the law in his new hometown, Smith was busted again in another state on similar charges, according to usually reliable sources.

Once again, these sources report, Smith’s newest favorite relative, his Uncle Sam, rode to the rescue.

The U.S. attorney’s office, the FBI, and the U.S. Marshal’s Service — the operators of the federal witness program — all declined to comment about the matter.

The arrests are just the latest twists and turns in Smith’s remarkable roller coaster ride as a cooperating witness. It began about five years ago, when he fingered Joel “Joe Waverly” Cacace and agreed to testify that the Colombo wiseguy had ordered him to kill William Aronwald. Joe Waverly pleaded guilty in 2004 and is due out of prison in 2020, but when and how Smith’s journey ends is anybody’s guess.

Understandably, it is the younger Mr. Aronwald, now a lawyer in private practice, who has been most upset about the feds’ blind spot to the man who helped kill his father.

Saying he had heard about Smith’s recent arrest from a “confidential source,” Mr. Aronwald wrote a December 13 letter to Judge I. Leo Glasser, who sentenced Smith but had been kept in the dark about his transgressions.

Mr. Aronwald told Gang Land he wrote his first letter to Judge Glasser three weeks after he raised the issue with Assistant U.S. Attorney Patricia Notopoulos. Mr. Aronwald said the prosecutor gave him “a runaround,” telling him some of his information was correct but some was wrong, refusing to elaborate.

“She said she really can’t comment except that some of what I heard was not accurate,” Mr. Aronwald said.

In a December 14 reply, Ms. Notopoulos confirmed that Smith had been arrested six weeks earlier but gave no details, noting that her “office has not interfered with the normal process of Smith’s new criminal case or any punitive consequences that may result.”

In his response five days later, Mr. Aronwald sagely pointed out that Ms. Notopoulos was “silent” about any help that her office’s partners, the FBI and U.S. Marshal’s Service, may have given Smith. Mr. Aronwald, a former federal prosecutor who headed the Manhattan Organized Crime Strike Force in the 1970s, also expressed outrage that her letter suggested that Smith was bounced from the federal witness program, when in fact he wasn’t.

“I am appalled,” Mr. Aronwald wrote, “that the government deems it more important to shelter and protect Smith, a life-long thug, than to take whatever steps are necessary to bring him back before you so that he can be re-sentenced for violating the terms of his probation. Smith is a coward who participated in my 78-year-old defenseless father’s killing and clubbed another man into a coma that ultimately resulted in his death.”

“Insofar as my father’s murder is concerned,” he wrote, “I wonder if the U.S. Attorney’s Office would have offered the same deal if the assassination plot involved one of their own.”

Meanwhile, Judge Glasser angered Mr. Aronwald by suggesting in a reply letter that the lawyer should address his concerns regarding a probation violation to the same U.S. attorney’s office that had spurned him a month earlier.

But Smith’s hijinks allegedly continued.

Sources said Smith was busted again for grand larceny, this time for switching price tags on plasma TVs. (Apparently, no one gave him one for Christmas.) After spending a day or so in jail, sources said, Smith called some old FBI contacts who helped him win a release on bail, under the ever watchful eyes of the Witness Protection Program.

All in all, the low-level crimes are quite a comedown for the murderous hoodlum. After a 1990s prison meeting with Jimmy “The Gent” Burke, who pulled off the daring $6 million Lufthansa Airlines robbery featured in the movie “Goodfellas,” Smith talked openly about one day being a successor of sorts to the legendary Irish gangster.

Smith’s biggest admirers these days appear to be his federal protectors, much to Mr. Aronwald’s chagrin.

“My understanding,” he said yesterday, “is that the court is forwarding my correspondence to the Probation Department for a response,” as is the norm in the case of unprotected defendants, but not in those involving cooperating witnesses.

“There’s nothing I can do but wait to see what comes out if it,” he said, adding that he recognized the need for the federal government to protect cooperating witnesses, but that in Smith’s case the government should be protecting the public from him, not the other way around.

“If I knew where he was,” he said, “I would make sure that everyone in his community, just like they do with convicted sex offenders, knew what his real name was, what crimes he committed, essentially the kind of person he was, and is, so they could protect themselves from him.”

This column and other news of organized crime will appear today at ganglandnews.com.