BOISE -- Police say catching the man responsible for a string of area armed robberies is currently the "top priority" for the department.

The robber struck again Monday afternoon at the Motel 6 at 2323 W. Airport Way in Boise. Boise Police Sgt. Justin Kendall said the hold-up, which happened at about 3:20 p.m., marks the sixth robbery investigators have linked to the suspect since Feb. 20.

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Five of those robberies happened in Boise, and one in Nampa. Kendall said investigators are working around the clock to figure out who the robber is and stop him before he targets another business.

"These cases are our top priority right now. We want to catch him," he said. "That's what all the detectives in my unit are working on right now."

The man is described as a thin, black man in his 20s. Witnesses in the Motel 6 robbery described him as wearing black and gray clothing and having a deep voice. Police say the man was spotted leaving an earlier robbery scene in a gold-colored sedan.

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Kendall said investigators have conducted interviews and collected evidence, including surveillance images, at each of the robbery sites. But the department still needs help from the public to catch the suspect, he said. Police are particularly interested in hearing from anyone who may have captured photos or video of the robber or his car.

No one has been in the robberies, police say, but each crime comes with the increased risk of something going haywire.

"Anytime you start getting these armed robberies, there is a threat to the public, there is a threat to these businesses and witnesses, and people that could walk in during these, so we definitely want to catch this guy and get him off the streets," Kendall said.

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He said it is rare for one suspect to get away with so many heists for so long - in part, because Treasure Valley residents are typically helpful about keeping their eyes open and calling in tips when they see something suspicious. In this case, Kendall believes the man is stake out businesses for some time before robbing them.

"We believe this guy is spending a considerable amount of time maybe doing some surveillance ahead of time," he said. "I think he's spending some time in the area to where people are probably seeing him and just not realizing that he's a suspect."

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Crime Stoppers is offering a cash reward to anyone who can help police solve the string of crimes, and tipsters can remain anonymous. Anyone who recognizes the suspect or has any information about the robberies is urged to call Crime Stoppers at 343-COPS or police at 377-6790.

"We just need that one break from somebody calling in and helping us out a little bit," Kendall said.