CHICAGO (CBS) — Police Supt. Garry McCarthy said a bloody holiday weekend that saw at least eight people shot and killed and dozens others wounded “doesn’t wipe out” reductions in violent crime in the past two years.

Since Friday evening, at least eight people were shot and killed in Chicago, and at least 44 others were wounded, police said

“This doesn’t wipe out what has happened over the last two years, and this is a conversation that we’ve had time and time again,” Police Supt. Garry McCarthy said Monday morning. “There’s no magic formula here. We have a plan, we have a strategy, and it’s hard work. That’s what it is. … It’s a day-by-day, minute-by-minute grind, and we’re into busy season. That’s what it is.”

Although murders in Chicago spiked to 516 in 2012 – only the second time homicides surpassed 500 since 2003 – they dropped to 415 last year, the lowest murder total for Chicago in nearly 50 years.

The superintendent said the vast majority of shootings in Chicago are gang-related, and detectives were working to determine “which of the hot conflicts” were to blame for the most recent spate of violence.

Mayor Rahm Emanuel said addressing the violence isn’t just about what the police do but what the schools, community groups and parents do to instill values in their children.

“You can’t do this just by discussing how many police we have and counting heads. You can’t do this by figuring out many kids are in after school. We have to do all of that and more and we all know we have tough budgets,” said Emanuel.