Question: Who developed the bomber that was shot down and killed Lieutenant Wally Marais?

Context paragraphs:
RCAF Western Air Command: Western Air Command was the part of the Royal Canadian Air Force's Home War Establishment responsible for air operations on the Pacific coast of Canada during the Second World War.  When Canada declared war against Germany in September 1939 the command consisted of only five squadrons.  Four of them equipped with obsolete aircraft including a bomber squadron with aircraft from the Great War and there were no fighter aircraft at all for its only fighter squadron (113 Fighter Squadron was thus disbanded).  With the Japanese threat after Pearl Harbor it grew rapidly and played a critical role in fighter and anti-submarine operations in Canadian and American waters during the Aleutian Islands Campaign.  It was there that Squadron Leader K.A. Boomer of No. 111 Squadron shot down a Rufe fighter, the RCAF's only kill in the Pacific Theatre.  On 7 July 1942 a Bristol Bolingbroke pressed home an attack on the Japanese Submarine Ro 32 the pilot F/Sgt.  P.M.G. Thomas of No. 115 Squadron RCAF then led American Destroyers to sink the damaged submarine.  By January 1943 Western Air Command had expanded to include many bomber, fighter and operational units under its control.  By the end of the war the command would involve some twenty squadrons when the last units to join were added in 1943.  These were the 163 Army Cooperation Squadron in March flying Bristol Bolingbrokes and Hawker Hurricanes, in May the 160 Bomber-Reconnaissance Squadron was added flying Cansos from Sea Island BC (before moving to Yarmouth NS in July) and the 166 Communication Squadron formed in September flying various types.  In addition to the new squadrons, new aircraft types came on line replacing the command's remaining Supermarine Stranraers and Blackburn Sharks with Canso's and the Bolingbrokes and Beauforts with the Lockheed Ventura.  Countless training missions and operational patrols bolstered the air activity over the coastal areas but there was not much action until RCAF Western Command was on the look out for General Kusaba's Fire Balloons that the Japanese called the Fūsen Bakudan Campaign.  In February and March 1945, P-40 fighter pilots from 133 Squadron, Royal Canadian Air Force operating out of RCAF Patricia Bay (Victoria, British Columbia), intercepted and destroyed two fire balloons, On 21 February, Pilot Officer E. E. Maxwell While shot down a balloon, which landed on Sumas Mountain, in Washington State.  On 10 March, Pilot Officer J. O. Patten destroyed a balloon near Saltspring Island, British Columbia.  During another interception a Canso forced down a fire balloon which was examined at the army headquarters.  Patrol activity was joined by the Operational Training Schools (OTS) operated by Number 4 Training Command of the BCATP.  They were the No. 3 OTS flying the Canso and Catalina and No. 32 OTS with Ansons, Beauforts and Swordfish at Patricia Bay.  In April, 1944 the No. 5 OTS Heavy Conversion unit stood up at Boundary Bay when 16 B-24 Liberators arrived fresh from American factories.  By the end of September 1944 RCAF 5 O.T.U. had grown to sizeable force of some 87 aircraft including 38 B-24 Liberators, 35 B-25 Mitchells, 5 Bolingbrokes, 8 P-40 Kittyhawks and a single Norseman.  With the end of the war in Europe these aircraft were joined by a number of Victory Aircraft Lancaster X bombers which were to be used to train the British Commonwealth's Very Long Range Bomber Tiger Force that would soon be sent to bomb the Japanese mainland from Okinawa.  With the unconditional surrender of Japan the RCAF's Tiger Force bomber squadrons were disbanded before they flew overseas and the total draw down of the Western Air Command was suddenly undertaken.  Within several months almost all the flying squadrons would be completely stood down.

English Electric Canberra: The English Electric Canberra is a British first-generation jet-powered medium bomber that was manufactured during the 1950s.  It was developed by English Electric during the mid-to-late 1940s in response to a 1944 Air Ministry requirement for a successor to the wartime de Havilland Mosquito fast-bomber.  Amongst the performance requirements for the type was the demand for an outstanding high altitude bombing capability in addition to flying at high speeds.  These were partly accomplished by making use of newly developed jet propulsion technology.  When the Canberra was introduced to service with the Royal Air Force (RAF), the type's first operator, in May 1951, it became the service's first jet-powered bomber aircraft.

Robert Saundby: Air Marshal Sir Robert Henry Magnus Spencer Saundby {'1': ", '2': ", '3': ", '4': "} (26 April 1896 – 25 September 1971) was an RAF officer whose career spanned both World War I and World War II.  He distinguished himself gaining five victories during World War I, and was present during the air battle when Lanoe Hawker was shot down and killed by Manfred von Richthofen, the "Red Baron".  He is chiefly remembered for his role as Deputy AOC in C Bomber Command under Sir Arthur 'Bomber' Harris during the latter part of World War II.

Messerschmitt Me 264: The Messerschmitt Me 264 was a long-range strategic bomber developed during World War II for the German "Luftwaffe".  It was intended to serve as Germany's main strategic bomber.  The design was later selected as Messerschmitt's competitor in the "Reichsluftfahrtministerium"' s (the German Air Ministry) "Amerika Bomber" programme, which intended to develop a strategic bomber capable of attacking New York City from bases in France or the Azores.  Three prototypes were built, but production was abandoned to allow Messerschmitt to concentrate on fighter production while another design, the Junkers Ju 390, had been selected in its place as a maritime reconnaissance aircraft.

December 2010 Bajaur bombing: On 25 December 2010, at least 47 people were killed and over 100 others injured, after a female suicide bomber detonated her explosives in a large crowd of people displaced by fighting, who were collecting food at a distribution centre of the World Food Programme in the Pakistani town of Khar, which is located within the Bajaur tribal region, of north-western Pakistan.  It was later reported by witnesses, that the bomber dressed in a full-length burka had reportedly thrown a grenade after resisting search, to which then the bomber proceeded to detonate her explosives.  Several police officials confirmed the bomber was a woman, as opposed to the more likely occurrence of a man wearing the burka as a disguise, in order to successfully conduct this suicide attack.  It was also known that those in this crowd were predominantly displaced members of the Salarzai Tribe, which has supported Pakistan Army operations against the Pakistani Taliban within the Bajaur tribal regions.  Those dozens of people injured in this suicide attack were apparently later taken to local hospitals via means of helicopters.  Local Witnesses, including that of a government official at the main government hospital within the region, Dosti Rehman, claimed that he had personally counted some 40 bodies.  However there are concerns that the death toll could very likely rise, as the official stated that several of those injured, as a result of this suicide attack were apparently in a critical condition at the local hospitals.  This particular bombing acts as one of a string of recent suicide attacks, which have occurred with near impunity, predominantly throughout Pakistan's north-western, Khyber Pakhtunkhwa Province, of north-western Pakistan.  No particular militant group has of yet claimed responsibility for this suicide attack, although the Pakistani Taliban are strong suspects.  The Bajaur tribal region has reportedly seen several Pakistan Army military operations in recent years, however such suicide attacks still continue throughout the region with near impunity.  The Pakistani Prime Minister, Yousaf Raza Gillani later condemned this suicide attack, and claimed that such military offensives would continue against the Pakistani Taliban.  This statement will be met with a certain degree of approval in the U.S, as Pakistan has recently been pressured to launch a major ground-offensive in the nearby North Waziristan tribal region, in order to root-out and destroy the last major remaining safe-haven for Radical Islamist and Pakistani Taliban insurgents within the country.  The U.N World Food Programme later suspended its food distribution activities in the Bajaur tribal region, as a security precaution to this suicide attack.  This suicide bombing was strongly condemned by U.S president, Barack Obama.  The Pakistani Taliban later claimed responsibility for this suicide attack.  This suicide bombing was officially declared the first such suicide attack to involve a female in Pakistan.

Operation Rekstok: Operation "Rekstok" (Operation Horizontal Bar) was a series of South African raids into southern Angola on 7 March 1979 during the South African Border War and Angolan Civil War.  The operation lasted six days.  Operating from Ovamboland, SADF forces entered Angola and attacked SWAPO bases at Mongua, Oncocua, Henhombe and Heque.  During the operation, a SAAF Canberra bomber was shot down, killing Lieutenant Wally Marais and Second Lieutenant OJ Doyle.  The SADF conducted Rekstok concurrently with Operation Safraan and later performed Operation Sceptic.

May 2010 Kabul bombing: The May 2010 Kabul bombing occurred on May 18, 2010, in Kabul, Afghanistan.  Eighteen people including five US soldiers and a Canadian soldier were killed and fifty-two were injured when a NATO convoy was targeted by a Taliban suicide attacker.  It was the deadliest attack against NATO forces in Afghanistan since September 2009 when six Italian soldiers were killed by a suicide bomber.  Two full colonels and two lieutenant colonels were killed in this attack making it the deadliest attack against ranking officers in Afghanistan.  With this attack the total number of Americans killed in Afghanistan crossed one thousand.

August 2013 Quetta bombing: On 8 August 2013, a suicide attacker exploded a bomb at a funeral being held for a police officer in Quetta, Pakistan, and killed as many as thirty-one people and injured over fifty people.  No group has taken responsibility for the bombing, but it is believed that the Taliban were behind the bombing.  A senior police officer, Fayaz Sumbal, noticed the suicide bomber before he blew himself up.  As Fayaz began searching the suicide bomber's body, the bomber blew himself up.  The bomber was wearing a jacket that had ball bearings and shrapnel inside.

Vickers Valiant: The Vickers-Armstrongs Valiant was a British four-jet high-altitude bomber, once part of the Royal Air Force's V bomber nuclear force in the 1950s and 1960s.  It was developed by Vickers in response to Specification B.35/46 issued by the Air Ministry for a nuclear-armed jet-powered bomber.  The Valiant was the first of the V bombers to become operational, and was followed by the Handley Page Victor and the Avro Vulcan; it was noticeably less advanced than its counterparts.  The Valiant has the distinction of being the only V bomber to have dropped live nuclear weapons.

Marais des Cygnes massacre: The Marais des Cygnes massacre ( , , or ) is considered the last significant act of violence in Bleeding Kansas prior to the outbreak of the American Civil War.  On May 19, 1858, approximately 30 men led by Charles Hamilton, a Georgian native and proslavery leader, crossed into the Kansas Territory from Missouri.  They arrived at Trading Post, Kansas, in the morning and then headed back to Missouri.  Along the way they captured 11 Free-Staters, none of whom were armed and, it is said, none of whom had participated in the ongoing violence.  Most of the men knew Hamilton and apparently did not realize he meant them harm.  These prisoners were led into a defile, where Hamilton ordered the men to shoot.  He even shot and fired the first bullet himself.  Five men were killed.

Supporting paragraphs: Operation Rekstok English Electric Canberra
Answer: English Electric