A Long Beach man has been charged with causing the package bomb explosion at a day spa in Aliso Viejo that killed the man's ex-girlfriend and injured two others in 2018, according to a federal criminal complaint unsealed Monday.
FBI agents said in the complaint they could find "no meaningful differences" between components used to construct the bomb and items discovered during a search of Stephen William Beal's home hours after the blast.
Beal, 59, faces a single charge of "malicious destruction of a building resulting in death," according to court documents reviewed by NBC News. He was re-arrested near his home Sunday by FBI agents, who used a truck to tear-off Beal's garage door and spent hours searching the house.
The explosion happened May 15, 2018, inside an office building at 11 Mareblu St. in Aliso Viejo, when the two surviving bombing victims said they saw spa owner Ildiko Kranjnyak open a cardboard box. Kranjnyak was Beal's former girlfriend.
"Victim #1 saw it explode and recalled being blown backwards by the explosion onto the floor," the complaint said. "She also saw flames and smoke."
Kranjyak, a mother and cosmetologist, had just returned to California after visiting family in her native Hungary. She was killed instantly and the explosion was so powerful human remains were found outside the building, authorities said.
Beal contacted law enforcement that day and told investigators he and Kranjyak were business partners and had recently ended a romantic relationship, according to an affidavit filed by an FBI agent.
During a search of Beal's home approximately 130 pounds of explosive precursors, electric matches and wire were discovered, which Beal explained were supplies he used in constructing model rockets.
The FBI agent said bits of wire recovered from the bombing scene were later compared with wire found at Beal's home.
"Both items contained 24-25 American Gauge wire, with the same color plastic insulation," the agent wrote. "Based on the metallurgic and paint/polymer chemistry, FBI laboratory personnel stated that no meaningful differences were observed."
The agent said chemicals detected at the blast site were similar to chemicals detected on swabs taken from inside Beal's car, that Beal purchased a battery consistent with one found at the scene about a week before the explosion at a store in Long Beach, and that Beal bought three cardboard boxes similar to the bomb package eight days before the explosion. Some of these purchases were recorded on security video, the FBI said.
Cellphone records and security video also showed Beal visited the salon building four days before the explosion, the agent said, and Beal told investigators he had one of the keys to the day spa offices.
Beal was initially arrested on suspicion of possessing explosives in the days after the bombing but was released without charges. Federal officials said at the time they had questions about whether the explosive precursor material found in Beal's home met the legal definition of a "destructive device."
While he was not publicly named a suspect in the bombing several law enforcement sources told NBC News in recent months Beal remained the focus of the bombing investigation.
A formal announcement by the US Attorney's Office and the Orange County Sheriff's Department was expected Monday morning.