Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. How a Perfect Storm of Forces Spiked US Homicides and Shootings Masood Farivar WASHINGTON - In sending federal law enforcement agents to several cities beset by a spate of shootings and violence, U.S. President Donald Trump is primarily laying the blame on politically left-leaning mayors and governors and efforts to "defund" police departments. "To look at it from any standpoint, the effort to shut down policing in their own communities has led to a shocking explosion of shootings, killings, murders, and heinous crimes of violence," Trump said Wednesday as he announced dispatching federal law enforcement agents to Chicago and Albuquerque, New Mexico. "This bloodshed must end. This bloodshed will end." But experts say the picture ismore complicated than the one the president paints. Although overall crime levels declined this year as people stayed home during the COVID-19 pandemic, a perfect storm of forces has led to spikes in homicides and shootings in many cities in recent weeks. Meanwhile, murder rates have declined in other cities. Criminologists say the exact drivers of the violence are hard to pinpoint. But they cite several contributing factors. Among them: warm summer weather, more people on the streets as states reopen their economies and a growing erosion of public trust in law enforcement amid the continued protests over the death of African American George Floyd while in police custody in Minneapolis in May. "There has certainly been an increase in homicides and shootings this summer, but it is not possible to tell whether this is due to the pandemic, other factors, or just typical variation," said David Abrams, a University of Pennsylvania professor of law and economics who has been tracking crime during the pandemic. Here are some key factors in understanding theviolence: Where are the killings and shootings happening? Most, though not all, major U.S. cities are seeing a spike in homicides and shootings. On average, homicides in 25 major American cities surged by double digits through early July. .