Portions of the nanny cam footage were aired on television Tuesday as police sought the public's help in identifying the man responsible for the attack, which occurred Friday morning in Millburn, a suburb of about 20,000 residents just west of New York.
Police Capt. Michael Palardy said he was revolted by what he saw the man do to the woman on the video.
"There was no reason for him to touch her at all because she would have willingly gave him what he wanted," Palardy said. "I've probably gone through this video 20 times, and it still sickens me every time I see it. He had no regard for her life. He didn't care if she lived or died."
Police withheld the woman's name to protect her identity and requested the faces of her and her child be blurred when the video was aired.
The woman suffered a concussion, bruises, chipped teeth and cuts around the mouth that required stitches, police said. It's believed she was knocked unconscious when tossed down the stairs, then awoke and called police. She was treated at a hospital and was released.
The nanny cam footage shows the woman sitting next to her child in front of the TV, then getting up to check out a noise out of the frame. It then shows her backing up and being attacked by a man who rushes her.
The burglar made three trips upstairs to rifle through the family's belongings, police said, assaulting the woman on the trips back to the first floor, kicking her, punching her and yanking her by the hair.
"It really takes a sick person to be able to do that," Palardy said.
The woman screams at the beginning of the assaults, which took place over several minutes, but then is quiet as her 3-year-old remains glued to the couch.
"I knew that if I started screaming, my daughter would, too, and I was afraid she would get hurt," the woman told News 12 New Jersey. "I took it. I didn't cry the entire time."
Police said the attacker made off with jewelry, which News 12 said included the woman's wedding ring. Neither the 3-year-old girl nor a 1-year-old boy upstairs was injured.
The police captain said he hoped the girl would not be permanently scarred by what she witnessed.
"She's a little girl, just 3 years old," he said. "Hopefully she can forget this."
A $5,000 reward was being offered for information leading to the arrest and conviction of the attacker, authorities said.
"We're confident we're going to catch him and the residents will feel safe again," Palardy said.