The FBI has apprehended a suspect in connection with last month’s car explosion at a fertility clinic in Palm Springs, California, according to three law enforcement sources on Wednesday.

Daniel Park, a 32-year-old from Kent, Washington, was detained on Tuesday night at New York’s John F. Kennedy Airport, one source reported. Details about the charges against Park or his link to the case remain unclear at this time.

The FBI identified Guy Edward Bartkus as the perpetrator of the fertility clinic attack; he perished in the blast. Authorities had initially explored the possibility of Bartkus having accomplices.

Federal prosecutors are expected to release details at a news conference in Los Angeles. The arrest was first reported by NBC News. The law enforcement officials spoke on condition of anonymity because they were not authorized to discuss a criminal case that has not been publicly disclosed.

Authorities have described Bartkus as a member of the anti-natalist movement, a fringe group that opposes childbirth and population growth and believes people should not continue to procreate. Officials said he intentionally targeted the fertility clinic as an act of terrorism. He tried to livestream the explosion, but the attempt failed, the FBI says.

The blast gutted the American Reproductive Centers fertility clinic in Palms Springs and shattered the windows of nearby buildings along a palm tree-lined street. Witnesses described a loud boom followed by a chaotic scene, with people screaming in terror and glass strewn along the sidewalk and street. A body was found near a charred vehicle outside the clinic.

Investigators haven’t said if he intended to kill himself in the attack or why he chose the specific facility. The clinic he attacked provides services to help people get pregnant, including in vitro fertilization and fertility evaluations.

Authorities executed a search warrant in Bartkus’ hometown of Twentynine Palms, a city of 28,000 residents northeast of Palm Springs with a large U.S. Marine Corps base. Authorities haven’t shared specifics about the explosives used to make the bomb and where Bartkus may have obtained them.

A senior FBI official called the explosion possibly the “largest bombing scene that we’ve had in Southern California.”

Scott Sweetow, a retired ATF explosives expert, said the amount of damage caused indicated that the suspect used a “high explosive” similar to dynamite and TNT rather than a “low explosive” like gun powder.

Those types of explosives are normally difficult for civilians to access, but increasingly people are finding ways to concoct explosives at home, he said.

“Once you know the chemistry involved, it’s pretty easy to get stuff,” Sweetow said. “The ingredients you could get at a grocery store.”

The images of the aftermath also showed that the explosion appeared to blow from the street straight through the building and to the parking lot on the other side, something that could have been intentional or pure luck, Sweetow said. A part of the car was also blown through the building and landed in the back by a dumpster.