Galveston County Sheriffs Office(SANTA FE, Texas) -- The teenager who allegedly opened fire in a Texas high school and killed 10 people studied previous mass shootings before carrying out the attack, sources told ABC News.

Dimitrios Pagourtzis, 17, researched tactics used by other mass shooters, the sources said.

He studied previous mass shootings and used aspects of those [attacks] in his own ...

iStock/Thinkstock(SANTA FE, Texas) -- She arrived from halfway around the globe but 17-year-old Sabika Sheikh was determined to bring her native Pakistan closer to America, the Texas family who took in the foreign exchange student told mourners at her funeral on Sunday.

Politicians, religious leaders, and friends packed the Masjid al-Sabireen mosque in the Houston suburb of Stafford to celebrate...

ABCNews.com(WASHINGTON) -- President Trump said in a tweet Sunday that he is ordering the Department of Justice to "look into" whether his 2016 presidential campaign was improperly "infiltrated or surveilled" for political purposes.

Trump added that hed ask whether "any such demands or requests were made by people within the Obama Administration."

The president said he would make the order offic...

Amazon.com(WASHINGTON) -- President Trumps top economic adviser said Trump may feel that theres some unfairness going on in regard to Amazon but said he couldnt comment in detail on the presidents concerns about the giant online retailer because he hasnt been deeply involved in those discussions.

Larry Kudlow, director of the National Economic Council, was responding to ABC News Chief Anc...

Rosalind OConnor/NBC(NEW YORK) --Nicki Minajis headed back toSaturday Night Livetomorrowas the shows season finale musical guest. The long-running sketch comedy series announced the rappers appearance back in April viaTwitter.

Three promos for the episode, starring Minaj and scheduled guest host and formerSNLcast member and head writer Tina Fey have also been released. One shows T...

iStock/Thinkstock(NEW YORK) -- The only way to test for symptoms of stomach or esophageal cancer is to undergo an upper endoscopy, a test that can be invasive, cost thousands of dollars and has a small percentage of success in actually finding a tumor.

Researchers in the U.K. wanted a diagnostic tool that would be easier and cheaper to test for these cancers so they used a noninvasive breath tes...