Houston police are searching for the man who robbed a northside woman at knife-point as she was walking her 7-month-old granddaughter.

It happened around 9:30 a.m. in Stuebner-Airline Park, 9200 Veterans Memorial Drive. Yolanda Reyna had taken her granddaughter, Alina, for a stroll around the park's half-mile walk when a man with a knife came out of the bushes.

Reyna said he held the knife to her side and demanded money. When she told him she didn't have any money, she said he searched the baby's stroller but found nothing.

"I told him I don't have nothing but my cell phone and my keys," Reyna said. "And then he say 'Okay, I take your keys.' He say, 'You call the police; I come back and do something to (you).'"

Reyna, a widow, said all she thought about was keeping her granddaughter safe. After the robber took off in her 2007 red Ford Escape, she called police and then the baby's mother. 

She reached her daughter at the dermatologist's office where she works. Jackie Reyna said she was terrified.

"I was in shock. I couldn't drive, I had to stop. I just couldn't believe it happened to my mother here in our neighborhood where things like this don't normally happen," said Jackie Reyna.

Neither the baby or Reyna was hurt, but they won't be going back to the park anytime soon.

Reyna described the suspect as a black male, about 5 foot 9 inches tall, slender build with short cropped hair. Reyna says he was wearing a camouflaged shirt and trousers, and threatened her with a folding knife.