SAN ANTONIO - A Texas woman who for months was unable to qualify for food stamps pulled a gun in a state welfare office and held a seven-hour standoff with police that ended with her shooting her two children before killing herself, officials said Tuesday.

The 10-year-old boy and 12-year-old girl remained in critical condition Tuesday. Authorities identified the mother as Rachelle Grimmer, 38, and children Ramie and Timothy.

When the family entered the office on Monday shortly before it closed, Grimmer asked to speak to a new caseworker, and not the one whom she worked with before, Texas Department of Health and Human Services spokeswoman Stephanie Goodman said.

Grimmer was taken to a private room to discuss her case, then she revealed a gun and the standoff began, Goodman said.

Police negotiators stayed on the phone with Grimmer throughout the evening, but she kept hanging up, Laredo police investigator Joe Baeza said. She allegedly told negotiators about a litany of complaints against state and federal government agencies.

Grimmer let a supervisor go unharmed around 7:45 but stayed inside the office with her children. After hanging up the phone around 11:45, police heard three shots, and a riot police team entered the building. Inside, they found Grimmer's body and her two wounded children.