BOSTON (CBS) – Boston police canine units were back on Boston Common Wednesday, searching for evidence in a shooting that left a teenager in critical condition.

Three teens were taken into police custody shortly after the shooting but were released after questioning, according to investigators.

They will remain people of interest as the injured 19-year-old recovers at Tufts Medical Center. He had been shot multiple times and was found wounded near the Parkman Bandstand around 7 p.m Tuesday.

Police said the victim knows the shooter.

Boston Mayor Marty Walsh said he’s outraged by the brazenness of the shooting, but both he and Boston Police say there’s been no uptick in crime on the Common though there are issues with drugs and homelessness.

While police stepped up their presence Wednesday, Antonia Chronis hopes it doesn’t stop there. “We used to see the park rangers, we used to see the police a lot more. I don’t think they’re around as much.”

Liz Vizzey with Friends of the Public Garden agreed that the drug and gang activity was a problem in the park. She said the wide open Common shouldn’t become an armed camp, though security should be reviewed.

Vizzey said, “The challenge is the park is public and open for everybody but the people who are up to no good need to feel disrupted.”

She pointed out that “the park rangers are understaffed and under-resourced.”

Jamie Thompson works on the Common.

“You get an unsettling feeling, definitely, when you are walking past the area where things happened.”

Elizabeth Goldman lives nearby.

“I heard loud gunshots. I was on the phone with my sister and I actually said out loud to her, ‘this sounds like gunshots,'”

While Goldman said it the shootings were not common in the area, she was not surprised.

“I think things can happen anywhere. I think that there’s more of a chance of it happening in a downtown urban area where you have a lot of people.”

Walsh said lighting and other improvements in the area could be part of a multi-million dollar plan potentially slated for next year.