FORT COLLINS, Colo. -- The targets of a series of home invasions in Fort Collins have something in common: medical marijuana.

Fort Collins investigators reported an alarming increase in robbers forcing their way into homes at gunpoint in recent months. In at least two cases, the robbers thought the victims were on the medicinal marijuana list.

Detectives said that with multiple groups of robbers kicking in doors all over Fort Collins, it is just a matter of time before an innocent person gets hurt.

They said many of the home invasions are going unreported because the victims don't want police attention.

"Which limits our ability to find people who are preying on other people," said Detective Marc Neal, with Fort Collins police. "What we’re afraid of is if they hit the wrong house, that it's innocent people who now become victims."

Police said because of the rash of home invasions, police want people in Fort Collins to be aware and take precautions.

"If you're not expecting someone, don't answer the door, and call police if you're suspicious of the person there," said Neal.