PHILADELPHIA (CBS) — Philadelphia district attorney Seth Williams calls the starvation and dehydration death of an infant in a shelter “a sad and disgusting set of facts.”

The victim’s mother, Tanya Williams (above), has been charged with murder (see previous story), but authorities are investigating to determine whether others should also be held responsible.

DA Seth Williams says two-month-old Quasir Alexander weighed 4½ pounds at birth but lost nearly a pound and had not been fed adequately for at least a month before he died.  He had also suffered a skull fracture.

DA Williams says the family had been receiving services from the city’s Department of Human Services, and the nonprofit Lutheran Children and Family Service has acknowledged providing services while the family was at the Travelers Aid shelter.

“We have to continue to invesitagate to see if there are actors, those who were providing services that did not provide the requisite standard of care pursuant to their professional responsibilities,” DA Williams said on Monday.

Representatives of DHS, Lutheran Childrens and Family Services, and Travelers Aid have all promised full cooperation with the investigatigation.

Reported by Tony Hanson, KYW Newsradio 1060.