Question: what gun that was also a .30 caliber semi-automatic carbine was used in the Daingerfield church shooting? 

Context articles: Ruger Standard
Ruger Police Carbine
M1 Garand
SKS
.300 Remington Ultra Magnum
Calico M960
Daingerfield church shooting
M1 carbine
M1917 bayonet
Demro TAC-1

The Ruger Standard model, also known as the Ruger Mark I, is a rimfire semi-automatic pistol introduced in 1949 as the first product manufactured by Sturm, Ruger & Co., and was the founding member of a product line of .22 Long Rifle cartridge handguns.
 It was marketed as an inexpensive .22 caliber rimfire intended for casual sport and target shooting, and plinking.
 Designed by company founder William B. Ruger, the Standard model and its offspring went on to become the most accepted and successful .22 caliber semi-automatic pistols ever produced.
The Ruger Police Carbine is a pistol caliber carbine designed as a companion to the Ruger P Series pistols.
 As of 2007, Ruger has discontinued production citing low demand.
 It is a semi-automatic carbine using a blowback action.
 The Carbine uses the same ammunition and magazines as the Ruger P Series 9mm and .40 S&W caliber pistols.
The M1 Garand is a .30 caliber semi-automatic rifle that was the standard U.S. service rifle during World War II and the Korean War and also saw limited service during the Vietnam War.
 Most M1 rifles were issued to U.S. forces, though many hundreds of thousands were also provided as foreign aid to American allies.
 The Garand is still used by drill teams and military honor guards.
 It is also widely used by civilians for hunting, target shooting, and as a military collectible.
The SKS is a Soviet semi-automatic carbine chambered for the 7.62×39mm round, designed in 1943 by Sergei Gavrilovich Simonov.
 Its complete designation, SKS-45, is an initialism for Samozaryadny Karabin sistemy Simonova, 1945 (Russian: Самозарядный карабин системы Симонова , 1945; Self-loading Carbine of (the) Simonov system, 1945).
 The SKS-45 was manufactured at Tula Arsenal from 1949-1958 and at Izhevsk Arsenal in just 1953 and 1954, resulting in a total Soviet production of about 2.7 million carbines.
 In the early 1950s, the Soviets took the SKS carbine out of front-line service and replaced it with the AK-47; however, the SKS remained in second-line service for decades.
 It is still used as a ceremonial firearm today.
 The SKS was widely exported, and was also licensed for production by then Eastern Bloc nations, Romania and East Germany, as well as China, where it was designated the "Type 56 Carbine".
 The East German version was known as the Karabiner S, the Albanian as the Model 561 and North Korean as the "Type 63".
 The SKS is popular on the civilian surplus market as a hunting and marksmanship semi-automatic rifle in many countries, including the United States, Canada, and New Zealand.
 Its age and numbers make it relatively inexpensive to purchase, and steel cased 7.62x39mm ammunition is one of the least expensive center fire cartridges currently on the market.
 The SKS was the second firearm to be chambered for the 7.62×39mm M43 round, with the first being the RPD.
The .300 Remington Ultra Magnum, also known as the .300 Ultra Mag' or .300 RUM is a 7.62 mm (.308in.)
 caliber rifle cartridge, 7.62×72mm, or .30 caliber rifle cartridge introduced by Remington Arms in 1999.
 The .300 Remington Ultra Magnum is one of the largest commercially available .30 caliber magnums currently being produced.
 It is a beltless, rebated rim cartridge, capable of handling all large North American game, as well as long-range shooting.
 Among commercially produced .30-caliber rifle chamberings, the .300 Remington Ultra Magnum is second only to the .30-378 Weatherby Magnum in cartridge-case capacity.
The Calico M960 is a 9×19mm (Luger/Parabellum) caliber semi-automatic carbine (fully automatic versions are available only to authorized law enforcement and military), manufactured by Calico Light Weapons Systems.
 Its features include its high-capacity, cylindrical, helical-feed magazine and retractable stock.
 This method allows magazine capacities of 50 and 100 rounds in a relatively small space.
 The rear sight is mounted as part of the plastic magazine shell.
The Daingerfield church shooting was a mass murder that occurred at the First Baptist Church in Daingerfield, Texas, United States on June 22, 1980.
 Alvin Lee King III, a former high school teacher, armed with a scoped, semi-automatic AR-15, an M1 carbine, and two revolvers, killed five people and wounded 10 others, after members of the church had declined his request to appear as character witnesses in a trial in which he was charged with raping his daughter.
 King was arrested after shooting himself and charged with five counts of murder and ten counts of attempted murder, but committed suicide in his prison cell on January 19, 1982, before he could be convicted.
The M1 carbine (formally the United States Carbine, Caliber .30, M1) is a lightweight, easy to use, .30 caliber (7.62 mm) semi-automatic carbine that was a standard firearm for the U.S. military during World War II, the Korean War and well into the Vietnam War.
 The M1 carbine was produced in several variants and was widely used by not only the U.S. military, but by military, paramilitary and police forces around the world.
 It has also been a popular civilian firearm.
The M1917 bayonet was designed to be used with the US M1917 Enfield .30 caliber rifle, as well as with the seven different U.S. trench shotguns.
 The blade was 16 inches (40.6 cm) long.
 It will not fit the M1903 .30 caliber (Springfield) or the M1 .30 caliber (Garand) US service rifles as they have different bayonet ring (barrel) and attachment stud dimensions.
The Demro TAC-1 is a semi-automatic carbine chambered in either .45 ACP or 9×19mm Parabellum.
 The TAC-1 is the reintroduction of the Fox Carbine to the law enforcement market after a fallout between Gerry Fox, the inventor, and Dean Machine Inc. of Manchester, CT.
 Although it is visually similar to the Thompson submachine gun the operation and design is quite different.
 The design is a closer cousin to the Russian PPSh-41.
 The TAC-1 and its predecessors are one of the few open bolt firearms that it is grandfathered by the BATFE and is legal to own and sell in the United States.