PHILADELPHIA (WPVI) -- Philadelphia police said Thursday it appears that five different guns were used during the deadly mass shooting on Memorial Day in Fairmount Park.
The gunfire left two people dead and nine others with gunshot wounds.
No arrests have been made and no suspects have been identified.
Police continue to ask anyone with information call them at 215-686-TIPS (8477) or submit an anonymous tip online.
Investigators are also reminding the public of the $20,000 reward offered in all Philadelphia homicides for information that leads to an arrest and conviction.
The gunfire erupted around 10:27 p.m. Monday on Lemon Hill Drive at Poplar Drive.
The two people killed were identified as 23-year-old Amya Devlin and 21-year-old Mikhail Bowers.
The victims who were wounded range in age from 15 to 28 years old, all of whom were last reported to be in stable condition at area hospitals.
Police Commissioner Kevin Bethel said Tuesday that investigators are confident that at least one of the weapons used in the shooting had a device known as a "switch" on it, which allows a semiautomatic weapon to become fully automatic.
In the video, you can hear the rapid bursts of gunfire.
An online video captured the sounds of Monday night's shooting and is now being used in the investigation.
Action News gave a first-hand look just last year at how this small attachment changes a semi-automatic weapon into a fully automatic gun.
Mayor Cherelle Parker signed a switch bill into law last year, banning gun attachments in the city.
A federal law makes devices modified with a switch illegal. However, Pennsylvania does not have a law banning them.
RELATED: Law enforcement officials across Pennsylvania work to get gun 'switches' banned
Bethel says there are usually a lot of people in the park when it gets warm, especially on a holiday, and that officers were managing crowds all over the city.
The shooting occurred despite officers' presence in the park, Bethel said.
"We try to manage the crowds as they unfold, but at the same token, it is a challenge when individuals decide that they're going to fire into a crowd," Bethel said.
Bethel said his team will be coming up with a plan to put more officers into the park so they can put a stop to potential incidents before they get out of control.
"Right now, the intelligence coming through our portal is not fast enough. We need to evolve, so we're going to be putting in law enforcement assets into the park to identify activity ahead with the hope that we can stave off these activities before they occur," Bethel said on Tuesday.