A motorist has been charged with murder after police say he ran down a woman and her three children in a Los Angeles crosswalk. Officers say 30-year-old Martin Gonzalez Valadez was driving drunk at the time of the accident. He faces four counts each of murder and gross vehicular manslaughter while intoxicated and is being held on $4 million bail. Prosecutors say Valadez had been drinking with his girlfriend when they got into an argument while driving Wednesday. The woman stopped the van and got out. Authorities say Valadez jumped into the driver´s seat and drove off. Witnesses say the van was speeding when it struck Evelia Sanchez and her children. A two-year-old and a three-year-old died at the scene. The woman and her five-year-old daughter were pronounced dead at a hospital.