Police divers had searched the lake in Echo Park, on the edge of downtown, for two days after hearing from Jessica Cortez' 5-year-old brother that she might have toppled in. At the same time, other officers went door to door interviewing witnesses around the park, and police concluded late Monday that she had been abducted.
Los Angeles police Capt. Douglas Shur told CBS Radio News investigators now think Jessica has been kidnapped.
Several people recognized a composite drawing of the man as someone who frequented the park regularly with his brown Chihuahua dog, Shur said.
Police are interviewing "witnesses that we have found that encountered this individual in the park last week...(He) was the last person seen with Jessica," Shur said.
Among those recognizing the drawing were the girl's parents who made a tearful plea in Spanish for her return.
"Don't be afraid of police. Please return her safe. Please bring her back," her father said.
Jessica, who was last seen wearing a white dress with pink flowers, was at Echo Park with her parents and brother Sunday when the family discovered she was missing at about 7:30 p.m.
Sometime between 8 and 9 p.m., Shur said, witnesses saw her in the park with the man accompanied by a brown Chihuahua dog.
He described the man as a male Hispanic, 20 to 25 years old, 5-feet-8 to 6-feet tall, with a tattoo of a cross on his lower left leg. He was last seen wearing blue shorts and a white T-shirt.
"This is our best lead that we have in locating young Jessica," Shur said. "We hope that he will come forward and give us information so that we can find her safe and sound."
Police, who had originally issued an "Amber Alert" for Jessica on Monday morning, reissued it Monday night.
Such alerts are named for 9-year-old Amber Hagerman, a Texas girl who was kidnapped in 1996 and later found dead.
The first Amber Alert for Jessica was issued at about 5:50 a.m., but was retracted a half-hour later after police reclassified the incident as a missing child case and not an abduction.
The system, which alerts news and media outlets of child abductions, was deployed statewide after the July 15 kidnapping and murder of 5-year-old Samantha Runnion who was carried kicking and screaming from her Orange County home.
Authorities credited it with leading them to two teenagers who were abducted at gunpoint from Lancaster, Calif., last week. Kern County sheriff's deputies, responding to tips from the public, tracked down the girls, rescued them and shot their abductor to death.