The incident involving the woman happened Tuesday outside of Northgate Market near Bristol Street and McFadden Avenue.
A mother of two young children, who wanted to be identified only as Karina, said the man was riding a bicycle and came out of nowhere.
"I was walking with the stroller, with my baby, and we were going to the store, going to Northgate ... He came up behind me to touch me," she said.
She added, "I screamed when he did that. There were people watching. They asked me if I was ok. They thought I knew that person."
Karina had little time to react but that's when she noticed something happened to her 5-year-old daughter.
"I didn't see. Some people told me what he did to her. She was only grabbing her neck. I asked her and she said he had grabbed her by the neck," the mother recalled.
Karina said the man, who's been identified by police as 30-year-old Moises Hernandez, only uttered the words "I'm sorry" before riding off.
Officer Natalie Garcia, the public information officer for the Santa Ana Police Department, said the suspect was arrested a short time later.
"A records check revealed that the suspect has done this numerous times before," she said. "He was out on parole for sexual assault."
Garcia said about an hour before the assault on the mother, Hernandez did the same thing to minors outside of a school nearby.
"In that incident, two females were near a high school when the same suspect had exposed his genitals and then grabbed one of the victims," said Garcia.
Hernandez is facing multiple charges, including sexual penetration by foreign object and force, indecent exposure, battery, lewd act upon a child and resisting public or peace officer. Karina said the whole situation has been traumatizing for her entire family.
"Right now, I go outside and I only look to the sides because I'm scared," she said.
When asked how her daughter is doing , she said, "She is ok. She's just a little scared to when she goes outside."