Boyfriend pleads guilty in fatal Long Beach barbell pipe attack on girlfriend's mother

An ex-New York City correction officer pleaded guilty Friday to murdering his girlfriend's mother by inflicting a vicious beating after sources said his girlfriend, also charged in the Long Beach slaying, recently struck a deal to testify against him.

Ralph Keppler, 29, pleaded guilty in Nassau County Court to murder, conspiracy and weapon charges in the death of Theresa Kiel under a deal in which he's expected to spend 22 years to life in prison.

Prosecutors said Keppler wielded a metal barbell pipe while attacking the Long Beach woman in the entrance of her New York Avenue apartment complex at about 10:30 p.m. on Dec. 4, 2016.

The former Malverne teacher, who suffered severe brain damage and a shattered skull, was hospitalized in a vegetative state for nearly two years before dying in November 2018 at age 56.

Keppler told Acting State Supreme Court Justice Christopher Quinn as part of his guilty plea that he conspired with the victim’s daughter, Francesca Kiel, to commit the slaying.

Last week, Francesca Kiel, 22, also pleaded guilty to murder while striking a deal to testify against Keppler as a cooperating prosecution witness, according to sources with knowledge of the case.

Under the deal, which remains sealed, the victim’s daughter will go to prison for 13 years, the sources said.

The guilty plea of Keppler, who worked on Rikers Island before his arrest, won’t change the terms of the daughter’s deal, according to the sources.

The deadly assault was connected to a business dispute, according to prosecutors.

Keppler, who had lived with Francesca Kiel in Lynbrook, filed a lawsuit before the attack claiming he and his family gave Theresa Kiel and her son, Vincent Kiel, money to develop a dating app but she wasted it.

Keppler "was remarkably calculating in his plan to murder Theresa Kiel,” stalking her for more than a week before the brutal attack, Nassau District Attorney Madeline Singas said in a statement Friday.

Singas credited police and members of her staff with unraveling the slaying plot and making sure Keppler was held accountable.

Singas’ office declined to comment Friday on the case against Francesca Kiel. A grand jury indicted her last year on murder, conspiracy, criminal facilitation and hindering prosecution charges.

“I’m sure just as Mr. Keppler was anxious to put this tragedy behind him, I can assure you Miss Kiel is equally anxious to put it behind her,” attorney Geoffrey Prime, who represents Francesca Kiel, said Friday.

“I cannot confirm or deny it,” Prime said, when asked if his client was a cooperating prosecution witness.

The victim’s brother, Michael Albano, her son Vincent, some of her former school district colleagues and Long Beach police officials were in court for Keppler's plea — as were Keppler's parents.

“We’re still in mourning and I’ll be in mourning the rest of my life,” Albano said later.

The district attorney’s office had alleged Francesca Kiel “served her mother up on a silver platter” to Keppler for the deadly beating.

Internet searches linked to an email account of Francesca Kiel showed a search of topics that included “easiest way to kill someone” and “single skull death blows,” prosecutor Stefanie Palma said previously in court.

The daughter ordered a GPS tracking device, put it on her mother’s car and followed her, according to prosecutors. They said she also called a cab for Keppler after the attack.

Keppler’s attorney, Marc Gann, said previously his client was the victim of a “setup” and many people had reason to attack the victim because of a “significant financial dispute” connected to the lawsuit in which she and Keppler were involved.

Gann said Friday that Keppler decided to plead guilty because he is guilty and wanted “to spare everyone” the trial process.

The Mineola attorney also said while he couldn’t confirm that Francesca Kiel had become a witness against his client, he believed that “to some degree” it weighed into his client’s decision to plead guilty. Gann said Keppler wanted Kiel “not to end up with a life sentence.”

The Mineola attorney added: “I don’t know that it necessarily mattered so much that she was cooperating against him but it was important that she end up without a life sentence.”

Prosecutors had said Keppler's DNA and the victim's blood were on the murder weapon — found in the vicinity of the attack. 

They also said Theresa Kiel, at some point before her beating, texted a friend and said Francesca had left school and moved in “with a psychotic sociopath who wants to kill me and Vince.”

In a text Keppler sent Vincent Kiel, prosecutors said he had warned: “Your mother will be in for quite the surprise too, but I’ll let you two ponder upon what would be in store next.”

After the assault, according to prosecutors, Keppler sent a text about Theresa Kiel to a friend that said: “Whoever tried killing her or mugging her is probably gonna finish the job.”