PHOENIX - The 12 News I-Team got more than 28 million hits when doing a simple search online about how to make a homemade explosive device. 12 News notified the Bureau of Alcohol, Tobacco and Firearms before conducting the suspicious searches.

The alleged Texas bomber built his explosive devices with basic materials, including a low-level explosive, shrapnel and a steel pipe.

"There was componentry and the homemade explosive material that we found in the house and that's what we're most concerned about and making sure we were able to safely deal with that," said Fred Milanowski of ATF.

Homemade bombs are becoming increasingly popular and extremely dangerous. The Boston Marathon bombers used modified pressure cookers back in 2013. Investigators say they learned how to make the explosives by reading Al Qaeda's instructions.

In 2012, there was a scare in the Phoenix area. A suspect scattered flashlights across the Valley that were rigged to blow up when turned on.

All it takes is a simple search online for potential criminals to learn how to make a homemade bomb. When 12 News conducted a search, we discovered hundreds of articles and video tutorials. The ingredients required are so common that criminals can find them at stores like Home Depot and Walmart and on websites like Amazon.

Amazon came under fire last year after the site reportedly made it even easier for those to buy explosive supplies by placing the necessary ingredients in its "Frequently Bought Together" section.

Officials ask employees at stores where bomb-making supplies are sold to keep an eye out for customers buying them in large quantities. However, tracking the sales of these common household items is nearly impossible.