David Delacruz, 25

David Lopez Delacruz, 25, a Latino man, was found face-down in a hallway in a building in the 8900 block of Tobias Street with stab wounds. He was taken to a hospital, where he died. Delacruz was a day laborer from Mexico. Investigators said they believe he had quarreled with a group of other day laborers.

The quarrel turned into a fight, and someone stabbed him. Investigators say efforts to piece together information about Delacruz and others involved in the killing are complicated because of a near-complete absence of any official record of the men's existence in this country, and the fact that all involved have multiple, and not very unique, last names.

Update: LAPD Mission detectives have cleared this case. Alberto del Isidro, a Mexican national, was later arrested at his Palmdale work site. Detectives believe Delacruz had left the scene of the argument and returned with friends to back him up when del Isidro stabbed him. The argument may have had to do with excessive drinking.