Ephonia M. Green, owner of Couture Miss Bridal & Formal at her bridal shop in Upper Marlboro, Maryland on July 1, 2013. (Greg Dohler/The Gazette)

A Maryland woman who embezzled $5.1 million from a District-based nonprofit was sentenced to 46 months in prison Friday after a sobbing apology in court that proved unmoving to a federal judge.

“You strike me, despite your tears here, as a very skilled con artist,” said U.S. District Judge Beryl A. Howell in Washington before sentencing Ephonia Green, 44, of Upper Marlboro.

Green stole while working as a $56,000-a-year administrative assistant at the Association of American Medical Colleges. The association represents medical schools and teaching hospitals and administers the test known as the MCAT used in medical school admissions.

Green also owned a bridal shop called Couture Miss Bridal & Formal in Upper Marlboro and touted her work donating ensembles to military brides. In court filings, prosecutors say Green’s thievery kept the unprofitable shop afloat and that it was bankrolled with $1.8 million in stolen funds.

Green pleaded guilty in November to thefts that occurred over eight years starting in 2005, although at her sentencing she acknowledged having taken an additional $38,000 starting in 2000 — losses not previously made public. Green was hired by the association in 1998.

The association also disclosed in court Friday that Green had shredded incriminating records.

Green’s scheme started small but dramatically escalated, court files show. To divert money, she created phony invoices in the names of companies that closely resembled those of legitimate vendors that did business with the association, then approved them for payment into her own accounts. The plan unraveled when a bank noticed a discrepancy.

Her earliest thefts involved directing money to a corporate account whose address was a cemetery in Northwest Washington, according to the association.

Under her system, which was detailed in court, a spelling change of just four letters netted $3.7 million for Green when she created nearly 200 false invoices­ in the name of the well-known Brookings Institution public policy organization but deposited the checks into accounts she opened for her own “Brookings Institute.”

Green told the judge that “there is no excuse for my behavior” and said she had “heartbreak every day” over the theft. “This is not the person I am.”

In court, Frank Trinity, the association’s chief attorney, posed his own question: “How could this have gone on for so long undetected?” To which Howell quickly said, “That was one of my questions.”

Trinity said Green’s plot went unnoticed largely because of what he said was its sophistication. In addition, he said Green told those who noticed inconsistencies that they were mistakes by others that Green would remedy.

Prosecutors asked for a four-year sentence, while defense attorney William C. Brennan sought a three-year term. Green declined to comment after the sentencing and stood crying in a prayer circle in the hall. She was given 46 months for each charge, but the sentences will run concurrently.

In leaning toward the higher recommendation, Howell made clear her frustrations with Green, who has failed to follow through on a pledge in court to sell her house, vacation home, bridal shop and other assets in order to repay her ex-employer.

Some of those assets also are held in the name of Green’s husband, who has balked at selling, Brennan told the judge. But Howell said it “is troubling to me” that Green has been “unable to find a way to pay back any of those monies.”

The judge also said it “is simply shocking” that Green stole for years and shredded records. Green had two previous convictions, including one for embezzlement from an earlier employer, the judge noted, saying, “You clearly did not learn your lessons.”

At the time of her guilty plea, prosecutors agreed to allow Green to handle the sale of her house and store to try to capture any upturn in the housing market and profits she might make from wedding and prom seasons at the store. It is more common to allow federal marshals to oversee sales after a conviction — a step Howell said now will occur.

Brennan said Friday in court that it had been “a mistake” not to have the marshals handle the liquidation of assets because selling goods was not work defense attorneys usually do and had led to discussions at his office about how they would launch a sell-off: “a yard sale, eBay, an auctioneer?”

Green pleaded guilty to one count of theft concerning programs receiving federal funds and one count of engaging in monetary transactions in property derived from specified unlawful activity.

In court files, Brennan emphasized that Green’s relatives and church associates, as well as young people she mentored, repeatedly said her theft was “out of character” for a woman they knew to be compassionate and generous.

A 2013 Washington Post investigation revealed more than 1,000 “significant diversions” of assets at nonprofit organizations discovered during a Post analysis of federal disclosure records filed by groups across the country. Many of the diversions identified by The Post were described as acts of theft and fraud carried out by insiders, contractors and investment advisers.