Harris County sheriff's deputies said an armed man wearing a wig and lipstick robbed a northwest Harris County Walmart.

"That's unusual," Harris County Sheriff's Office Sgt. Mario Alvarado said.  "We have not seen a case like that in a while, where a suspect wears lipstick."

Authorities said the man walked into the Walmart on FM 2920 and Kuykendahl around midnight Wednesday with a specific target in mind. Deputies said the man rushed toward a cash cart being pushed by an employee.  The female employee tried to fight him off, but he pulled out a gun and she quickly relinquished control.

Before escaping with a getaway driver, another Walmart employee tried to block the robber's exit.

"As the employee tries to block him in, the suspect pulls a gun on (him) as well,"  Sgt. Alvarado said.

Investigators believe the suspect is familiar with the store, possibly a former employee, because he knew exactly where the cash cart was kept.

"That's another reason we think it's a former employee because he knew the routine," Sgt. Alvarado said.

Police said employees chased the suspect into the parking lot but he drove off with a getaway driver in a white or silver Ford Expedition.

No one was hurt.

Authorities are looking over surveillance video to gather more details about the robbery.