A California mother was reunited with her abducted son Thursday, after he vanished with his father 21 years ago.

Maria Mancia had been left with just one photo of her son after the boy's father took him at the age of 18 months in 1995. 

Steve Hernandez, 22 was found living in Puebla, Mexico, and on Thursday morning, was brought to the U.S. to meet his mother for an emotional reunion.

"Now this anguish I've carried is gone now that I have my son back," Mancia told KABC-TV. "I spent 21 years looking for him not knowing anything."

The San Bernardino County District Attorney’s Child Abduction Unit had been looking for Hernandez in several states through the years. Investigators said they received a strong tip in February that he was in Mexico.

Valentin Hernandez, Steve’s father, is missing and is believed to be dead, authorities said.

Investigator Karen Cragg, who led the search, said they had to approach Steve Hernandez delicately.

"We used a ruse to contact him. We told him we were investigating his father and we needed his DNA to help locate his father," Cragg told The Associated Press on Thursday. "We didn't want to scare him off. We weren't sure what the circumstances were down there. We had to tread very carefully."

Hernandez’s mother and father had been living in Rancho Cucamonga, Calif. in 1995. The parents were having relationship issues and one day when Mancia came home from work, both her husband and son were missing.

The father had taken all photos of their son from the home, including an ultrasound. Mancia had to write a relative in El Salvador to get a picture.

“I thought we were robbed, but then I noticed the only thing missing was Steven’s things and his clothes,” she told the San Bernardino Sun.

Mancia immediately reported her son missing and the investigation had been active ever since – first with the Sheriff’s Department and then with DA’s investigators.

Neither the mother nor her child was told when Steve Hernandez was first found, lest false hope be created.

Once the DNA sample was obtained in February, Cragg asked the Department of Justice if they could hurry on the test, knowing it could take several months.

"They called me in two weeks and said it was a match," Cragg said.

Cragg and her partner drove straight to Mancia's house.

"It was like she didn't believe us at first," Cragg said. "She began to cry. She said she couldn't believe he was still alive."

Because Steve Hernandez is a U.S. citizen, there were no immigration troubles returning him to the U.S., Cragg said. He had no personal documents at all, but his mother had his birth certificate and other identifying information.

The boy's father had told him that his mother abandoned the two of them.

He now knows that wasn't true. And he now knows his mother.

"I lived all these years without my mother, then to find out she's alive in another country, it's emotional," Hernandez told KABC. He said he plans to stay in the U.S. and hopes to attend law school, which he already started in Mexico.

He hugged his crying mother when he finally met her. Then wiped tears from her eyes.

The Associated Press contributed to this report.