Dad allegedly killed 5 of his infants: 'Monsters and killers cannot hide forever' If convicted, the father could face the death penalty.

A California father has been arrested for allegedly killing five of his infant children, in what the Yolo County, California, sheriff called the most disturbing case of his career.

Paul Perez, 57, is accused of killing the five infants -- all born between 1992 and 2001 -- by "lying in wait" and using torture, Yolo County District Attorney Jeff Reisig said at a news conference Monday.

It's believed all five were killed before turning 6 months old, Yolo County Sheriff Tom Lopez said. A motive is not known.

The investigation began in 2007, when a dead baby boy was found in a waterway near Woodland, California, near Sacramento, according to the Yolo County Sheriff's Office.

The baby was in a sealed container weighed down with heavy objects, according to the sheriff.

The baby's identity was unknown until October 2019, when DNA comparison determined he was Nikko Lee Perez, born in 1996 in Fresno, California, authorities said.

Investigators used the DNA to make a list of possible parents and siblings of the baby, which led to Paul Perez, said Edward Medrano, chief of the California Department of Justice's Division of Law Enforcement.

Nikko Lee Perez's identity also led to the identity of four of his siblings, who the sheriff said "suffered the same fate": Kato Allen Perez, born in 1992 in Merced, California; Mika Alena Perez, born in 1995 in Merced; another baby named Nikko Lee Perez, born in 1997 in Fresno; and Kato Krow Perez, born in 2001 in Fresno.

Kato Allen Perez is known to be dead, the sheriff's office said. The three other siblings are also believed to be murdered but their bodies have not been found, the sheriff said.

Perez was arrested at California's Kern Valley State Prison, where he was serving time for unrelated offenses, Lopez said. Perez's arrest came days before he was due to be released, Lopez said.

Science and "the power of DNA" show that "monsters and killers cannot hide forever any longer," Reisig said.

If convicted on the charges -- which include five counts of first-degree murder with special circumstances -- Perez could face the death penalty or life in prison without the possibility of parole, said Reisig. The district attorney's office has not yet determined if it will pursue the death penalty, said Reisig.

Perez is being held in the Yolo County Jail and is set to be arraigned Tuesday afternoon.

Lopez declined to say how the babies died.