The video shows the suspect pulling up to the store, walking in and asking an employee about flower arrangements.
Sister of the owner, Ma Ines Zepeda, walked in the back to begin the order.
The suspect is then seen in the front of the store, nervously walking back and forth.
He then pulls out a knife and attempts to open a small locked cash register several times.
WATCH: Surveillance video of floral shop robbery slowed down
After several failed attempts, he decides to walk to the back of the shop and confront Zepeda with a knife up to her throat.
"I thought he was going to kill me," she told ABC13 in Spanish. "I just felt the cold knife on my neck."
The suspect is seen forcing the worker to the register, where he demands her to open it.
She told him she didn't know how to and that she did not have the key.
But, she remembered she had a little over $300 inside her phone case, which she handed over to him.
He then pushed her to the ground and took off.
Houston police are now investigating, so if you know who this person is, call authorities.
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