Just before dawn on a recent Thursday, a SWAT team and detectives from Philadelphia's homicide unit quietly snaked through the streets of the city's Mayfair neighborhood. 

The overworked detectives were closing in on a possible murder suspect in the death of an immigrant Uber driver. Philadelphia saw 562 homicides in 2021 — more than ever before — and nearly half have gone unsolved. In this city, and across the country, the odds of getting away with murder are essentially a coin flip, the low point in a dramatic decline from the 1950s, when about 90% of murders led to arrests, according to FBI data analyzed by CBS News and an independent group, the Murder Accountability Project.

That's why Detective Joe Murray and his six-person squad were up at 4 a.m., moving toward the home where a person they believed was captured on surveillance camera shooting and killing the Uber driver before fleeing in a getaway car may have been holed up.