TACOMA, Wash. -- An eighth motel in the area has been hit in a struck of robberies that has been plaguing the area, according to police.

Det. Larry Andren said the Shiloh Inn in the 7400 block of South Hosmer Street was robbed just minutes before 8 p.m. on Thursday night.

The woman who was watching the counter had the doors locked and had to buzz in the thief, Andren said. Once inside, the crook wasted no time.

"Immediately ran, vaulted the counter, assaulted the clerk, took the money out of the till," said Andren.

The thief got away, but police have arrested his alleged getaway driver.

"That individual is refusing to give up the identity of the person," said Andren.

The distraught clerk said the man punched her in the shoulder and pulled her hair. She was shaken but was expected to be OK.

The incident at the Shiloh Inn came just a day after two other motels in the area were hit. Police have released surveillance footage that captured one of the robberies.

The footage captured by a surveillance camera at the Days Inn on Tacoma Mall Boulevard shows the crook jumping the counter and grabbing cash while a customer watches.

Investigators said there are similarities in the robberies which lead them to believe one thief is responsible for all of them.

The first robbery took place on Sept. 26. Six Tacoma motels, a Fife motel and a Federal Way motel have been hit.

Police said the thief doesn't carry a weapon but sometimes acts as if he is armed.

"In some of these, he has had his hand in his pocket, making people believe he might be armed," Andren said.

Police said the thief appears to be growing more brazen and more violent with each robbery he gets away with.

"He's physically manhandling the victims," Andren said, "likes to grab them, likes to throw them around a little bit. It's a power thing."

Anyone with information on any of the robberies is urged to call Crime Stoppers at 253-591-5959.