MIAMI (CBS4) – New information has been released in the kidnapping of a South Florida mother whose baby was found dead in the trunk of a car.

According to the Broward Sheriff’s Office, Janus Saintil, 24, of Deerfield Beach, killed his son Josiah on Friday, June 1st, when he put the child in the trunk of a stolen car while the baby was still strapped into his car seat, then covered him with a diaper bag and blanket.

CBS4 News has learned that Santil may have killed his son because the baby’s mother, Claudia Harriot, broke up with him on Thursday.

According to the police report, Saintil was with Harriot, Marissa Murray, Andrew Pennant and the baby in the parking lot of a North Lauderdale Walmart on Thursday night. While inside a black Kia, Saintil and Harriot got into an argument over their relationship.

Saintil, said police, pulled a gun and threatened everyone in the car. They then drove to a home in Port St. Lucie. BSO said Saintil dropped the baby off at an unknown address then took his victims to a second house in Port St. Lucie. Investigators say Saintil then took the group to an ATM, where Saintil tried to force one victim to get cash. The victim yelled for help and Saintil left in a black, four-door Kia Spectra. Someone spotted the terrified woman and called 9-1-1.

Operator: Ask the girl who is screaming, the one who said she is being held hostage, who is holding her hostage.

Caller: Who is holdy you hostage?

Operator: Is there a baby in the car? Is there a child in the car?

Caller: (yelling to woman) Is there a bay in the car? He has a gun too.

Operator: Who has a gun? She has a gun?

Caller: Who has a gun, the driver? The driver has a gun.

When police pulled over the driver and arrested Saintil, they found the child dead in the trunk.

BSO says Coral Springs Police developed information along with the U.S. Marshal’s Service that Saintil might be headed to an apartment complex at 11000 Royal Palm Boulevard.

Police say Saintil arrived in the stolen Kia with Harriott in the car and inadvertently parked next to a police officer who was looking for him. He was arrested without incident.

The officer searched the car and discovered little Josiah’s body in the trunk.

Saintil has been charged with First Degree Murder, Armed Carjacking, Armed Kidnapping, Aggravated Battery with a deadly weapon and a pre-existing Armed Robbery arrest.