In the tiny city of Piedmont, surrounded by Oakland, home invasion robberies are rare. But police are investigating two robberies that happened in one week, the latest in a spate of similar crimes.

On Monday morning, January 21, several male suspects kicked in the doors of two separate homes in Piedmont and robbed residents at gunpoint. Captain Scott Wyatt says during the second crime, one of the residents followed the suspects out of the house.

"At that point when the suspects saw the victim or victims," Wyatt said, "they fired a shot toward the house, we believe to frighten the victims back in while they were fleeing."

Monday's home-invasion robberies make a total of four since December. " I would say this is extremely unusual," said Wyatt. "If we have one a year, even that would be unusual."  The Piedmont police department is working with Oakland police to search for related crimes.