WOODLAND, Calif. (KCRA) — A man has been arrested in connection with the decades-old slayings of his five infant children, the Yolo County Sheriff’s Office announced Monday.

Paul Perez, 57, of Delano, is accused of killing his five children between 1992 and 2001, authorities said.

“This is not a day that will bring joy to anyone of us,” said Yolo County Sheriff Tom Lopez. “In my 40 years in law enforcement, I cannot think of a case more disturbing than this one.”

A fisherman discovered a deceased baby on March 29, 2007, in a waterway just east of Woodland. The baby boy was in a sealed container and weighted down with heavy objects.

Using DNA technology, the baby was identified in October 2019 as Nikko Lee Perez.

“We’re here because, as seen in other cases around the nation, the science and power of DNA has shown that monsters and killers cannot hide forever any longer,” Yolo County District Attorney Jeff Reisig said at a news conference Monday.

With the new information gleaned from DNA analysis, investigators learned Nikko had siblings. Kato Allen Perez was born in Merced in 1992 and is known to be deceased, the sheriff’s office said.

The three other siblings are also believed to be deceased, but their remains have not been located. They are: Mika Alena Perez, born in Merced in 1995; Nikko Lee Perez, born in Fresno in 1997; and Kato Krow Perez, born in Fresno in 2001.

“Yes, it is unusual. There’s actually the first Kato and then there’s a Nikko and another Nikko and then another Kato with a different middle name,” Lopez said. “So, that did raise suspicion on our part.”

“We were able to create a list of siblings or parents of the victim,” said Ed Medrano with the California Department of Justice. “That approach helped us to identify the probable father of the infant in this case.”

The Yolo County District Attorney’s Office is also alleging that the killings were committed by means of lying in wait and through torture. All of the children were younger than 6 months old, authorities said.

“This case revealed unspeakable evil,” Lopez said.

“There’s absolutely no place in society for these kind of horrendous crimes against our children,” Medrano said.

Perez was arrested days before he was due to be released from jail, Lopez said, adding, “The fact that he was not allowed to walk out of that prison a free man cannot be overlooked.”

Perez’s arraignment is set for Tuesday afternoon.

Lopez said the investigation is not over and leads are still being developed.

Anyone with information related to this case can contact the Yolo County Sheriff’s Office at 530-668-5280 or 530-666-8282. Anonymous tips can be reported at 530-668-5248.

This story contains information from CNN Newsource.