The discovery of a baby’s lifeless body in a waterway outside of Woodland has “haunted” his department since 2007, Sheriff Tom Lopez said.

A break in the cold case offered little comfort as it became clear the child’s death was part of a horrifying string of homicides involving four of his infant siblings.

Accused of killing five of his children between 1992 and 2001, Yolo County officials announced the arrest of 57-year-old Paul Allen Perez of Delano during a press conference at Yolo County Jail on Monday morning.

“While I’m proud of the efforts of my investigators and coroner’s office, this is not a day that will bring joy to any one of us,” Lopez said. “In my 40 years in law enforcement, I cannot think of a case more disturbing than this one. There can be no victim more vulnerable and innocent than an infant and unfortunately, this case involves five.”

On March 29, 2007, a fisherman found a sealed container weighed down with “heavy objects” at Conway Slough just east of town. The boy’s body was inside.

The case went without any leads until October 2019 when a DNA comparison identified the deceased as Nikko Lee Perez — born in Fresno in 1996.

“A missing person DNA program uploaded the infant’s DNA to the CODIS where it was checked every week for direct matches,” said California DOJ Chief Ed Medrano. “When those searches failed to yield results, we expanded our search to look for kinship-based matches. Using DNA technology developed by scientists at the California Department of Justice, we were able to create a list of potential siblings or parents of the victim. That approach allowed us to locate the probable father of the infant in this case.”

After the ID was made, “countless hours” were spent furthering the case to where it is now, according to Lopez.

Investigators found that Nikko had multiple siblings. Born in Merced in 1992, Kato Allen Perez was known to have died. Though their remains have not been located, law enforcement believes Mike Alena Perez born in Merced 1995, Nikko Lee Perez born in Fresno in 1997 and Kato Krow Perez born in Fresno in 2001 are dead as well.

Lopez noted that the kids had similar names, calling it “unusual” and “suspicious.”

The working theory is all five were under 6 months old when they were killed.

“While the break in the case began with DNA, and the importance of the DNA evidence cannot be overstated, it was the human element that led to this arrest,” the sheriff said.

Paul was arrested at Kern Valley State Prison while serving time for unrelated charges. When exactly he was arrested was not specified, but Lopez said he is currently being housed at Yolo County Jail.

He is scheduled to be arraigned in Yolo Superior Court on Tuesday afternoon.

“Today we are announcing charges against Paul Perez for the serial murder of five of his own children — all babies,” District Attorney Jeff Reisig said Monday. “We’ve also alleged that the murders were committed by means of lying in wait and through torture. We’ve also alleged multiple murders as a special circumstance.”

If convicted, Paul could face life in prison without the possibility of parole or the death penalty.

Reisig said his office is unsure whether it will seek the death penalty yet but will likely decide sometime this year after more facts are known.

Further details of the case were limited as the investigation is ongoing.

“We believe that there may be additional witnesses in this state who might remember Paul Perez or his children, and if they’re out there, one of our hopes from this press conference is that it will jog somebody’s memory and they will come forward and contact investigators and tell us what they know,” Reisig said.

Anyone with information related to the case is encouraged to contact the Sheriff’s Office at 668-5280 or 666-8282. Anonymous tips can be given at 668-5248.

In addition to the DA’s Office, Sheriff’s Office and California DOJ, Woodland and West Sacramento police departments, Sacramento Sheriff’s Office, California Department of Corrections, California Department of Public Health and the FBI contributed to the investigation.