Police say all of the 13 shootings they're investigating since January have been "targeted attacks."

And "one of the central themes to most of the shootings has been the drug subculture," said Supt. Ryan Diodati, head of the Hamilton Police Service Investigative Services Division.

Aside from the shooting death of a high-profile mobster, where motive is still unknown, the shootings all have a common thread of drugs, police said.

That includes Thursday morning's attack on the Mountain that sent a 39-year-old woman to hospital with a gunshot-related injury. On Sunday, there was a home invasion at the exact same home, where a man forced himself inside assaulted "multiple victims" before running away. Police didn't share details about that home invasion until Thursday.

Diodati said that might be due to "investigative techniques" being used in the case. He said the service believed the attack to be targeted and so did not see a public safety reason to alert the community.

None of the shootings are being treated as linked investigations, he said. Often the attackers are seeking drugs, jewelry or cash.

Police Supt. Ryan Diodati said a central theme in most of the 13 shootings is the drug subculture but they're otherwise not linked so far. <a href="https://t.co/sDD48RV7nl">pic.twitter.com/sDD48RV7nl</a> —@kellyrbennett

He said he didn't have statistics with him to compare this year's gun incidents with previous years.

"Obviously the numbers are concerning," Diodati said. "One incident, one shooting is concerning."

Chief Eric Girt told police board members Thursday that the guns in Hamilton being used for crime are predominantly handguns with some long arms as well.

"The bulk of the guns that make their way into this community in Hamilton are largely from Ohio," he said.

He said the service and provincial partners are tracing any guns they come across in their investigations.

Police are investigating a shooting on Holly Avenue on Tuesday morning, and searching for several suspects. (Samantha Craggs/CBC)

This most recent shooting is the latest in a string of gun violence in Hamilton in recent weeks.

There have been drive-by shootings, home invasions, and the shooting death of a high-profile mobster.

Shooting spike

Here's a list of shootings just within the last month:

Other than the charges laid in connection with Tuesday's shooting on Holly Ave., police have not announced any arrests in connection with these incidents.