The first of two Denver PSAs asking people to come forward with information to help solve gang violence cases.

Citing a significant increase in gang violence, Denver police and city officials unveiled on Wednesday two public service announcement videos asking people to come forward with information that could solve crimes.

The two videos feature the family of Marcus Mason, who was gunned down in 2007.  His murder remains unsolved, and his mother, Josephine Baez, pleads in the videos with witnesses of any gang violence to help police. 

"There’s too many people that know and don’t want to say, and I understand their fear. But by not saying anything you’re helping them get away, so you need to step up and say something," she said at a news conference Wednesday, when the videos were released.

Both videos include Josephine, and Marcus’s father, Carlos Mason.

"All I say is, you know, let’s quit living in fear. Let’s stop this senselessness. Just quit killing innocent kids. Let’s come together as a community and do something about this," he said.

Denver Police Chief Robert White says that of the 17 murders in Denver this year, 12 have been related to gang violence. And there have already been more gang-related homicides in Denver this year than in all of 2014. Many of these cases remain unsolved because witnesses are afraid, or unwilling, to come forward.

“This is a plea to the entire community. Very few crimes occur in our community where somebody other than the perpetrator witness what occurs," White said. 

White asked for tips, regardless of how insignificant they may be, to be called in at 720-913-STOP(7867). 

Denver Mayor Michael Hancock says police and volunteers have been out in the affected neighborhoods providing free LED porch lights, and the ATF has provided 15 HALO cameras to monitor targeted areas. It's part of what Hancock calls an “full court press” to combat an increasing number of shootings and other incidents.

Mike Mills, president of the Metro Denver Crime Stoppers, said that witnesses who come forward with information could receive rewards of up to $4,000. 

The second of two Denver PSAs asking people to come forward with information to help solve gang violence cases