Police Officer Dexter L. Mardenborough

Police Officer Dexter L. Mardenborough

Virgin Islands Police Department, Virgin Islands

End of Watch Sunday, January 27, 1991

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Dexter L. Mardenborough

Police Officer Dexter Mardenborough was shot and killed while pursuing a suspect after responding to a shooting call at a local nightclub on King Street in Christiansted.

When he arrived at the scene he observed three men fleeing the scene and gave pursuit.

One of the men took cover behind a building and then opened fire on Officer Mardenborough as he approached. Officer Mardenborough was struck once in the head and killed.

One of the subjets was arrested the following morning while attempting to leave the island at the local airport.

The man who shot Officer Mardenborough was arrested in New York, New York, in February 1991. He was determined to have also murdered Puerto Rico Police Department Agent Pedro Sanchez-Lopez and Agent Jose Bernabe-Gonzalez on September 6th, 1990. He was also linked to five additional murders in the Caribbean and New York City.


  • Age 22
  • Tour 2 years
  • Badge Not available

Incident Details

  • Cause Gunfire
  • Weapon Handgun
  • Offender Apprehended

foot pursuit, shots fired call

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I have tried to do it justice after so many years. This is a brief from the Puerto Rican press, about the case. IS RELATED TO THE OFFICER Dexter L. Mardenborough Murder and 2 other police officer in Puerto Rico. The same killer.



Melissa Correa Velázquez, EL VOCERO NEWSPAPER

On September 6, 1990, police officers José Bernabé González and Pedro Sánchez López, assigned to the Caimito police station, carried out a nighttime patrol when they were informed of an attempt to “carjacking” at a gas station in Cupey.

These responded to the 10-50 emergency call, went to the gas station located in the Olmedo Plaza shopping center and a chase was raised to the parking lot of the Villa Esperanza Public Complex.

Once in the public housing complex, the officers were shot by two subjects identified in the Police report as Adam Raymond Beníquez, better known as “Pipi” and who was on the list of the most wanted in the 90s; and William Valentín Mañón, who is currently waiting to be sentenced in a federal jail in New Jersey.

Officer Sánchez López was killed at the scene. Bernabe Gonzalez was seriously injured at the scene while trying to help his partner. He subsequently died while being treated at the Medical Center, in Río Piedras.

According to the complaint report, Beníquez and Valentín Mañón were subjected to the case in the absence of murder and robbery, after municipal judge Ángel L. Robles found probable cause. According to the report held by EL VOCERO, a bail of $ 601,000 was imposed on Beníquez.

The case was handled by the late prosecutor Iris Meléndez and prosecutor José Laclaustra. The investigation was done by the ex-agent of the Homicide Division, Beldredín Román Vélez.

An article contained in the archives of the New York Times newspaper of that time indicates that after the murder of the police on the Island, Beníquez fled to the island of Santa Cruz, where it is alleged that he shot the policeman Dexter Mardenborough in front of a disco club in 1991.

Subsequently, he moved to the neighboring island of St. Thomas, where he allegedly killed three other people and then settled in New York. He was arrested in that state in February 1991 for the assault and murder of a jewelry manager in Brooklyn, identified as Luis Medina. The arrest took place in a grocery store five blocks from where Beníquez perpetrated the assault on the jewelry store.

For this crime, he served 25 years in jail, after pleading guilty.

The website of the New York Department of Community Correction and Supervision states that Beníquez extinguished his sentence at the Attica criminal institution in that state. Sources in this media reported that about two months ago Beníquez served his sentence and remains on probation in New York. Man owns accounts on social networks.

However, Beníquez has not faced justice in Puerto Rico for the double murder of the agents, said a retired policeman who spoke with EL VOCERO on condition of anonymity. The former agent expressed his desire for justice to these two agents who lost their lives almost three decades ago in the line of duty.

The ex-agent commented that the fine policemen are not forgotten in Caimito police station, since the photo of both appears on a wall in recognition of their work.

Allege inaction of local authorities

Meanwhile, sources in the state of New York reported that the authorities of that city recently notified the government of Puerto Rico about the release of Beníquez and that they did not take action on the matter on the Island.

This newspaper requested a reaction from the Department of Justice and Secretary Dennise Longo indicated in written statements that “the Department of Justice, through the Office of the Chief of Prosecutors, is analyzing this case. The investigation dates back to events that occurred in 1990 and requires a thorough analysis to determine which evidence is still in force to prosecute the accused. Two prosecutors have been assigned to work the investigation together with Puerto Rico Police officers. ”

Longo added that "the public ministry reaffirms our commitment to achieve convictions and do justice in all cases with reliable and effective evidence."

The source states that it was not until this media requested a reaction to Justice on the matter that began to analyze the case.

The police report states that as a result of the investigative management of the agents, they found several eyewitnesses to the double murder who were taken sworn statements, by instructions of the prosecutor Meléndez.

Sources of this media indicated that the Bureau of Forensic Sciences (NCF) keeps the file of this case, in which it is detailed that they have the uniform of the murdered policemen and the bullet shells recovered at the scene, among other evidence.

Autopsies of the final agents were carried out by the pathologist Francisco Cortés.

Included in dismal list

Meanwhile, the Murderpedia website includes Beníquez in his list of serial killers. The publication includes the resolution of the Court of Appeals of New York, dated December 13, 1999, confirming the conviction of the individual on charges of second degree murder, theft and possession of a firearm.

The other person linked to the murder of the two police officers —Valentín Mañón— had cases of armed robbery in Miami Dade County, Florida, in 1996. On May 26, 2004, he was indicted by a federal grand jury in Puerto Rico for bank robbery by armed hand. He pleaded guilty to these charges and was sentenced to 24 years in jail and three years of probation, according to the electronic file of the Federal Court on the Island.

Meanwhile, according to a press release from the New Jersey District Attorney's Office, Valentín Mañón was charged with armed robbery at a jewelry store in Elizabeth, Newark. The subject was found guilty by a jury on February 15. The sentence is set for January 29, 2020 before Judge Madeline Cox.

Ret Officer CRUZ PRPD
Ret Puerto Rico Police Dept

February 24, 2020

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