Officers now say more than 400 firearms were seized at three sites after their undercover investigation.
Neighbors and friends say Seal had sold guns some years back from one of those locations. They say for a number of years he had a shop called the "War Bunker" at 309 Beardsley Ave.
On Tuesday, agents seized weapons from that location, from the home a couple blocks away, and from a site in Apple Valley in Riverside County.
A second suspect, Erik Stoffel, was also arrested in Apple Valley.
"California has laws that regulate the sales and purchase of firearms. These individuals broke the law by illegally selling firearms for personal profit," Attorney General Kamala Harris said in a Wednesday statement. She called that a serious threat to public safety.
The Department of Justice statement says the investigation started early this year.
"According to investigative documents, Seal was an official vendor selling firearms at California guns shows and Stoffel was a co-conspirator during Seal's attempts to complete firearms transactions at gun shows without going through a licensed firearms dealer, as required by law," their statement says.
Stoffel and Seal were in Apple Valley when the homes in Oildale were raided.
At 329 Beardsley, officers laid out blue plastic sheeting and lined up dozens of guns. Neighbors watched, stunned.
"I can't really believe that all that stuff was in their house," Kierstin Mathus told Eyewitness News. "The amount of guns that I saw right along that driveway was rather appalling."
Mathus said she didn't know the people living in the house.
"It's hard to believe who you think you know to be neighbors," she said. "You think they're just nice people, an older couple."
The Rasmussen Senior Center is a few blocks away, and Gene Thompson said Seal would have lunch there a couple times a week. Thompson was surprised at the number of weapons taken from the two homes on Beardsley but said Seal had sold guns for quite a while, as far as he knows.
"I ran into him at, they had a gun show at the fairgrounds a while back, and he was selling some of his old guns there," Thompson said.
Plus, Thompson and a neighbor told Eyewitness News Seal ran the "War Bunker" gun shop for a number of years.
"I don't know if it was just guns only," Thompson said. "I'm thinking something like an Army surplus kind of thing."
At the Tuesday raid, DOJ agents said two WWII-era grenades and one motor round were seized. That had caused more trouble in the Oildale neighborhood.
"We actually were being evacuated, so they made us leave," Kierstin Mathus said. "And, that's when the bomb squad showed up."
The raids on Tuesday were assisted by the Kern County Sheriff's bomb squad, and also California Highway Patrol officers.
The A.G's office says Seal is accused of firearm sales that included assault weapons, a large-capacity magazine, and sale to a "prohibited person."
"Over the course of the investigation, Seal and Stoffel illegally sold multiple firearms, including banned assault weapons, to undercover agents with the California Department of Justice," the statement reads.
Officials also said as of Wednesday morning, Stoffel had made bail, but Seal was still in custody on $50,000 bail.
That afternoon Seal's relatives told Eyewitness News they were in contact with a bail bond company, trying to get his release. And they were too upset to make any comment.
A neighbor who only wanted to be identified as Rita, said she was shocked at the number of weapons taken from the Beardsley Ave. home.
"My daughter gets off the bus right here down the street," Rita said. She said her daughter walks past that house, which had seemed nice and quiet. But, now she's relieved that all the weapons are gone. "Maybe it's a good thing that, you know, they're actually picked up, and now they can no longer cause harm to any other people."