HOUSTON -

Cool, calm, and collected. That's how authorities describe a man seen casually walking down a hallway in surveillance video obtained exclusively by Local 2.

Police say just as casually he's stolen nearly a dozen laptops from several businesses just by walking through the door, usually by blending in with after hours cleaning crews.

"The doors are unlocked, he's following them in," said Jeff McShan of Crime Stoppers. "And then getting access to these buildings, and going desk to desk."

Investigators say just last week the man walked into two office buildings on Saint Mary's Lane near the Katy Freeway and Dairy Ashford Road. Inside he snatched several laptops from three companies. The week before they say he pried open office doors in a building on the 800 block of Gessner near Barryknoll Lane. That time, stolen laptops from two companies.

"We think that he's perhaps done this at other businesses as well," said McShan. They just don't realize that these laptops are missing yet."

Authorities have also released a picture taken from surveillance video from one of the burglaries at the Saint Mary's location.

They believe if it's not the same suspect -- it's the same crime. There's also the possibility the thieves could be working as a team.

"It could be somebody that he's working with, or somebody completely different," said McShan.

Crime Stoppers is offering a $5,000 reward for information leading to the arrest and conviction of the suspect or suspects.