Criminal complaints against the man accused of killing his ex-girlfriend and her 3-month-old child say Ricardo Santiago murdered the two in their home — even though his victim's vehicle was found seemingly abandoned 15 miles away.

Police said early Wednesday 34-year-old Neidy Ramirez and 3-month-old Genesis Ramirez — last seen on Friday — were in fact murdered by Ricardo Santiago, 34, of Millville. But authorities haven't yet released details of the crime — what if any incident lead up to it, or how the two were killed.

In criminal complaints filed Wednesday, an officer said Santiago caused the deaths during a physical altercation at the Ramirez' E. Quince Street home on Friday.

But when the two were first reported missing, authorities said Neidy Ramirez's 2005 Chevy Trailblazer was found by State Police abandoned on Northbound Route 55 near milepost 45.3. The car had also been observed by a Ramirez family friend early Saturday morning, authorities said.

It isn't clear how the vehicle got to Route 55. Police haven't yet said whether they believe Santiago moved it, possibly to cover up the alleged murders.

"It is with deep sadness and regret that the Vineland Police Department announces the missing person investigation has now become a double homicide and recovery investigation," Vineland police said in an announcement Wednesday morning.

Vineland Police Lt. Matt Finley said police recovered the bodies in western Cumberland County, though he didn't specify exactly where. He said Santiago, 34, of Millville was cooperating with police after coming in for questioning.

According to a 6ABC.com report, Santiago led police to the bodies. Finley didn't confirm that when asked by New Jersey 101.5.

He declined to release more details of any incident leading up to the murder or how it was conducted, saying that information would later be released by the Cumberland County Prosecutor's office. The prosecutor's office has not yet provided a more detail account.

According to Vineland police, the mother and daughter were last seen on Friday November 27, 2015 in the Vineland area. Police didn't say how they identified Santiago, of Millville, as a suspect, only that a "collaborative joint investigation between the Vineland Police Department, New Jersey State Police and Cumberland County Prosecutor’s Office has identified the accused."

Santiago has been charged with two counts of homicide and is lodged in Cumberland County Jail in lieu of $1,000,000 cash bail. He and Neidy Ramirez had a 5-year-old child, but they did not live together, and he was not the 3-month-old's father, authorities have said.

After hearing the tragic news on Wednesday, neighbors of Ramirez were struggling to comprehend how something so violent could happen right next door.

"This is a shock," said longtime Vineland resident Agnes Sanchez. "We generally don't have anything that happens here."

Fellow resident Rodney Reyes said the whole incident is horrible, but the death of a baby is "one of the worst things in the world."

"I have a 2-year-old, so it hit home," he said.

A woman who lives in the same building as Ramirez said she hadn't noticed any drama among the former couple.

Co-workers of Ramirez at a local pasta shop, though, were aware of tension between Ramirez and Santiago.

Authorities are asking anyone with information pertaining to the investigation to contact Vineland Police Criminal Division Main Extension 856-691-4111 ext. 4180 or the Cumberland County Prosecutor’s Office at 856-453-0486.

— Dino Flammia and Louis C. Hochman