Maybe he was just trying to put together a big surprise for Mother's Day.

John Grzyminski found himself behind bars Thursday, a day after cops confiscated three pipe bombs from his Warrington home — including one discovered in the kitchen by his mother.

Grzyminski, 50, had "some sort of domestic verbal dispute" with his mom, Catherine Wilson, before she found that small explosive device in the house, on Saddle Drive near Carriage Way, said Special Agent Steve Bartholomew, a spokesman for the Bureau of Alcohol, Tobacco, Firearms and Explosives.

Wilson is listed on the deed as the owner of property. According to some news reports, she had recently tried to evict Grzyminski.

Bartholomew said Grzyminski was arrested Thursday after he was spotted in his truck by cops in Solebury Township, Bucks County. He was charged with risking a catastrophe, recklessly endangering another person and related offenses.

"They're firecrackers," Grzyminski said as he was escorted into a police station, according to Fox 29. "I'm not a terrorist." He said he was probably going to "take them out hunting ... You use them in the woods."

The pipe bombs were disabled by members of the Philadelphia Police Department's Bomb Squad Unit. Bartholomew said pieces of the explosives and other evidence from the house will be fingerprinted and analyzed at an ATF lab near Washington, D.C. The ATF is working with the U.S. Attorney's Office to determine if he should face federal charges, Bartholomew said.

He noted that no one was injured, and that the incident "isn't terrorism-related."

Little seemed to be known about Grzyminski by residents in his quiet neighborhood until the block became alive Wednesday with the roar of fire engines and the piercing sirens of swarming police cruisers.

"I've lived here for 10 years, and if somebody showed me a picture of him, I wouldn't know who he was," said Michele Starks, who lives on the same block. "We're a pretty tight-knit block. We have block parties at the end of the summer, and I don't ever remember him being there."

Starks said she was at home Wednesday when officials suddenly shut down the block and ordered residents to evacuate.

She said she returned home several hours after the evacuation, and found out about Grzyminski's pipe bombs when she turned on the news.

"It's really bizarre," she said. "We still don't know what his intentions were."

Contact staff writer David Gambacorta at 215-854-5994, or gambacd@phillynews.com or on Twitter @dgambacorta.