TULSA, Oklahoma - Downtown Tulsa has seen a spike in bike thefts in the past few weeks. Police have good surveillance pictures and hope you can help identify the suspected thieves.

Police say in all the cases the bikes were either locked up or sitting inside a building, but, they say if a thief wants it, they're going to get it.

Photos show a man leaving the back door of a coffee shop on North Main with a $1,000 bike that belongs to Robert Stewart, who rode the bike to work, took it inside and parked it just outside his office.

"It's just that violated feeling. This is my space, my comfort zone, and, all of a sudden, that's all gone," he said.

Seeing the man on camera, boldly walking into the business and taking a bike, put everyone on high alert.

"Everyone's on lockdown, keeping an eye on everybody, making sure we're communicating with everyone coming through the door, what they're up too, keeping an eye things," Stewart said.

Video shows a man walking into the parking garage of the downtown Hyatt, then, moments later, he rolls out on a $500 that had been locked to a bike rack moments earlier.

"Obviously used some kind of tool to cut it and walk out, kinda brazen, just 30 feet from the front entrance," Corporal Brandon Davis said.

Police said one man went into a parking garage and took a $5,500 bike off a rack that was attached to a vehicle. Officers recovered it, and, because the victim had his serial number, he got it back.

Police say if you want to protect your bike you should invest in a good lock, put a GPS tracker on it, write down the serial numbers, or, etch a specific number or name that can be identified back to you.