Question: Stephen Alley was allegedly involved in the murder of which Russian mystic?

Context paragraphs:
Ruth Wilson Epstein: Ruth Beverly Wilson was an American nurse married to alleged spy Jacob Epstein.  Epstein had been wounded in the Spanish Civil War after he volunteered for the International Brigades.  Ruth, who was a nurse, met him while he was recuperating from his injuries.  They were allegedly Soviet intelligence agents, who were stationed in Mexico City during World War II.  They were allegedly involved in the efforts to break Leon Trotsky's killer, Ramón Mercader, out of a Mexican prison.  Wilson's code name in Soviet intelligence and deciphered in the Venona transcripts is "Nona".

List of people allegedly involved in Russian apartment bombings: List of people allegedly involved in Russian apartment bombings

John Scale: Lieutenant Colonel John Dymoke Scale DSO, OBE (born 27th December 1882) was a MI6 (SIS) agent, originally from Merthyr Tydfil in Glamorgan.  He was involved in a British propaganda unit called the Anglo-Russian Commission in St Petersburg, where his responsibilities included running Mohammed Beck Hadjetlaché.  Scale served in the British Indian Army and was first sent to Russia in 1912.  He qualified as a Russian translator in 1913 and rejoined the 87th Punjabis in 1914.  In 1916, Scale served with Stephen Alley and Oswald Rayner under Mansfield Cumming at the time of the murder of Grigori Rasputin.  Whilst a Captain in St Petersburg, in the weeks leading up to the killing, Scale is recorded as having met with Oswald Rayner and Felix Yusupov in the diary of their chauffeur, William Compton.  Several other books and documentaries have claimed Scale's involvement in Rasputin's death, or even alleged that Scale commanded Rayner to fatally shoot him.  A letter from Alley to Scale provides the best evidence of British Intelligence involvement in the murder and torture that reads :

Stephen Alley: Captain Stephen Alley was an engineer and MI6 (SIS) agent born in a House of Yusupov Palace, Moscow, Russia.  He was educated in both Russia and England and became experienced in building rail transport.  He is noted by many authors and documentaries for alleged involvement in the murder of Grigori Rasputin whilst working for the British Military Control Office in Saint Petersburg.  Alley was alleged to be the author of a notorious letter to John Scale on 25th December 1916 that, if authentic, is claimed by BBC History to be "the best proof of British involvement in Rasputin's murder"

Philip Abramo: Philip Abramo (born 1945), also known as "The King Of Wall Street", "Lou Metzer" is a caporegime in the New Jersey DeCavalcante crime family who was allegedly involved in security fraud and murder.  Abramo was a capo of the DeCavalcante family's crew in Miami, Florida.

Jaybee Sebastian: Jaybee Niño Manicad Sebastian (born c. 1980 or 1981) is a Filipino inmate interred at the New Bilibid Prison (NBP) who was convicted for kidnap-for-ransom and carjacking in 2009.  He is known for running a prison gang inside the NBP and was allegedly involved in the illegal drug trade within the prison.  On September 28, 2016, Sebastian and two other inmates were injured, while a Chinese drug lord named Tony Co died after being involved in a stabbing incident in NBP Building 14.

Grigori Rasputin: Grigori Yefimovich Rasputin (Russian: Григорий Ефимович Распутин ] ) (21 January [O.S. 9 January] 1869  – 30 December [O.S. 17 December] 1916 ) was a Russian mystic and self-proclaimed holy man who befriended the family of Tsar Nicholas II and gained considerable influence in late imperial Russia.

RBG Resources: RBG Resources was a British public-limited firm based in London that was allegedly involved in a serious fraud worth close to £300 million (US$600 million).  RBG Resources made $1.1 billion in sales in 2000.  It was an affiliate of the United States based Allied Deals Inc., which was also involved in the fraud, and resulted in 14 people convicted or pleading guilty to related crimes.

Kartellen: Kartellen (English: "The Cartel") is a Swedish gangstarap hip hop group founded in 2008 by Kinesen with Babyface, both serving life sentences in Finland for accessory to murder.  Kinesen was also allegedly involved in an infamous airport multi-million robbery in 2002.

Nine Trey Gangsters: The Nine Trey Gangsters (also referred to as Nine Trey Gangstas) are a set of the United Blood Nation street gang, the latter of which is a set of the Bloods street gang.  The gang was established in 1993 at the Rikers Island jail complex in New York City, and operates on the East Coast of the United States.  The gang has operated in the U.S. state of Virginia and other states.  It has allegedly been engaged in the sex trafficking of their women and racketeering in Virginia, New York, North Carolina, Maryland and other areas.  The gang was also allegedly involved in the distribution of illegal drugs, including heroin, cocaine, crack, ecstasy, marijuana and prescription painkillers in these areas.  Further allegations include dealing in counterfeit U.S. currency and using counterfeit currency to "finance wholesale drug purchases".

Supporting paragraphs: Stephen Alley Grigori Rasputin
Answer: Grigori Yefimovich Rasputin