Baltimore County police investigating a man who shot a child in the leg with a pellet gun in February got a surprise when they searched his apartment in Owings Mills -- a pile of guns, ammunition, bombs, fuses and metal pipes.

In addition to bomb making materials, police said they found books with titles such as "The Anarchist Cookbook," "Blaster's Handbook," "The Chemistry of Powder and Explosives," "Improvised Radio Detonation Techniques," "The Do-It-Yourself Gunpowder Cookbook," "Home-Built Claymore Mines," and "Ragnar's Homemade Detonators -- How to Make 'Em, How to Salvage 'Em, How to Detonate 'Em."

Timothy Ray Berry, 28, pleaded guilty in U.S. District Court on Thursday to possession of firearms and explosives and faces up to 20 years in prison when he is sentenced on March 1. Here's what police said they found in his apartment:

The BB gun used in the assault, a loaded 9mm handgun, a 12-gauge shotgun, 3 boxes of ammunition, handcuffs, brass knuckles, other BB guns and airsoft pistols and a stun gun.  Police also observed "several improvised explosive devices, including: C-4 explosive material; and a clear plastic container with gray powder and a M-800 pyrotechnic device inside, secured with a white lid with a burnt hole in the center."

Authorities searched the apartment a second time and said they found "items commonly used in the production of illegal improvised explosives, including, among other things: containers of potassium nitrate and potassium chlorate, smokeless shotgun powder, model rocket igniters and motors, pool chemicals, various fuse materials, PVC and metal pipe of varying lengths and pipe fittings."

Police also said they found "numerous books related to firearm and the manufacture of illegal improvised explosives. Berry had underlined and starred book titles including, “Clear Your Record & Own a Gun,” and “How to Lose Your X-Wife Forever.”  Berry’s computer was also seized and a subsequent forensic analysis revealed that less than a month before, Berry had searched online for how to make homemade C-4, and how to fabricate tags for Maryland license plates."

The Maryland U.S. Attorney's Office said in a statement that on March 1, "following Berry’s arrest and detention on state charges related to child abuse, reckless endangerment, and gun possession, and with knowledge of the imminent federal investigation, Berry called another individual from jail and instructed that person to “burn” the “other books” and to get rid of “anything that looks like it could be suspect...”