The family of a Richfield man gunned down in his neighborhood last month is putting up a $10,000 reward in hopes somebody will come forward with the tip police need to catch those responsible.

It was a month ago that Jonathan O'Shaughnessy, 24, was fatally shot about 11:20 p.m. near the intersection of E. 64th Street and 4th Avenue S. as he walked home from a community dance.

Police described the July 3 incident as a "drive-by-style" shooting and said the assailants fired four to five rounds. Authorities have been searching for a late-model gray minivan, which sped away after the shooting with two men and possibly a woman inside.

"This is a despicable act of violence," said Richfield Police Chief Jay Henthorne during a news conference held with O'Shaughnessy's family on Thursday. "We cannot take enough tips. Please help us bring these individuals to justice who cut down this young man's life so early."

Henthorne said investigators would like to speak with two bicyclists who were in the area and might have seen the shooting of the Academy of the Holy Angels graduate.

O'Shaughnessy's family wants answers and said that's why they are putting up their own reward.

The family's reward comes as Crime Stoppers announced Thursday that it has increased its offer for information leading to the arrest and conviction of those responsible from $1,000 to $4,500.

"Somebody knows something and they can come forward," said Crime Stoppers chairman Robert Dennistoun.

Tips can be submitted anonymously through the nonprofit organization's website, crimestoppersmn.org, or a toll-free phone number, 1-800-222-8477.