Counterinsurgency Cops, Africa Mercy, Marfa, Texas - S45.E42

Lesley Stahl examines counterinsurgency tactics employed by police in Springfield, Mass., to combat gang violence; Scott Pelley goes aboard the Africa Mercy hospital ship, where thousands of Third World patients are treated for cataracts, facial tumors and cleft palates; Morley Safer visits cowboys and artists in Marfa, Texas.