The Black Museum, or The Crime Museum of Scotland Yard, is a collection of criminal memorabilia kept at New Scotland Yard, headquarters of the Metropolitan Police Service in London, England.
 The museum came into existence sometime in 1874, although unofficially.
 It was housed at Scotland Yard, and grew from the collection of prisoners' property gathered under the authority of the Prisoners Property Act of 1869.
 The act was intended to help the police in their study of crime and criminals.
 By 1875, it had become an official museum, although not open to the public, with a police inspector and a police constable assigned to official duty there.
The 1973 Old Bailey bombing was a car bomb attack carried out by the Provisional IRA (PIRA) which took place outside the Old Bailey Courthouse on 8 March 1973.
 The attack was carried out by a 10-person ASU from the Provisional IRA Belfast Brigade.
 The unit also exploded a second bomb which went off outside the Ministry of Agriculture in London on the same day at around the same time the bomb at the Old Bailey bomb went off.
 This was the Provisional IRA's first major attack on mainland Britain since The Troubles began back in 1969.
 One British civilian died of a heart attack attributed to the bombing, estimates of the injured range from 180 - 220.
 Two additional bombs were found and defused.
 Nine people from Belfast were convicted six months later for the bombing, and one acquitted for providing information to the police.
The October 2010 Abuja car bombings, also referred to as the 2010 Nigeria Independence Day attacks, were two car bombings carried out against crowds celebrating the fiftieth anniversary (golden jubilee) of Nigeria's independence in the capital city of Abuja on the morning of October 1, 2010 .
 The attacks left 12 dead and 17 injured.
 According to multiple sources, the Movement for the Emancipation of the Niger Delta (MEND) issued a warning less than an hour before the first bomb stating the location, near Eagle Square (the venue of the celebration), and the time, around 10:30 a.m., of planned bombings.
Hugh Feeney (born 1951) was a volunteer of the Provisional Irish Republican Army who, together with Dolours Price and Marian Price, organised the car bombings of the Old Bailey and Scotland Yard on March 8, 1973.
 He and ten members of his 11-man active service unit (ASU) were apprehended attempting to board a flight to Ireland shortly after the bombs were discovered.
Dolours Price (21 June 1951 – 23 January 2013) was, along with her younger sister Marian, a Provisional Irish Republican Army (IRA) volunteer.
 She was also a political activist who became a staunch critic of Gerry Adams' leadership of Sinn Féin.
Scotland Yard vs. Dr Mabuse (German: Scotland Yard jagt Dr. Mabuse , also known as "Scotland Yard Hunts Dr. Mabuse") is a 1963 German crime film directed by Paul May and starring Peter van Eyck.
Scotland Yard is a board game in which a team of players, as police, cooperate to track down a player controlling a criminal around a board representing the streets of London.
 It is named after Scotland Yard, the headquarters of London's Metropolitan Police Service.
 "Scotland Yard" is an asymmetric board game, with the detective players cooperatively solving a variant of the pursuit-evasion problem.
 The game is published by Ravensburger in most of Europe and Canada and by Milton Bradley in the United States.
 It received the "Spiel des Jahres" (Game of the Year) award in 1983.
Hale Hōʻikeʻike at the Bailey House (House of Display at Old Bailey House, formerly and commonly the Bailey House Museum) is a museum of Hawaiian history and art located in Wailuku, on the island of Maui, in Hawaiʻ i.
 It is owned and operated by the Maui Historical Society.
 Old Bailey House is a historic district contributing property within the Wailuku Civic Center Historic District, and is on the National Register of Historic Places.
The Central Criminal Court of England and Wales, commonly known as the Old Bailey from the street on which it stands, is a court in London and one of a number of buildings housing the Crown Court.
 Part of the present building stands on the site of the medieval Newgate gaol, on a road named Old Bailey that follows the line of the City of London's fortified wall (or "bailey"), which runs from Ludgate Hill to the junction of Newgate Street and Holborn Viaduct.
 The Old Bailey has been housed in several structures near this location since the 16th century, and its present building dates from 1902.
The July 2016 Qamishli bombings were a twin car bombing in a Rojavan-held district in the city of Qamishli, part of the al-Hasakah Governorate in Syria.
 The bombings killed more than 44 and more than 171 were wounded.
 The Islamic State of Iraq and the Levant praised the attacks and claimed responsibility.
 The city of Qamishli was also the site of multiple car bombings since 2015.

Question: What was the relationship between the two women who organized the car bombings of Old Bailey and Scotland Yard?
Answer: sister