A masked gunman robbed two D.C. Department of Corrections officials of more than $15,000 yesterday in front of a Northeast Washington halfway house, police reported. The loot, including more than $5,000 in cash and the rest in checks, belonged to people under the jurisdiction of the corrections department.

Police said the holdup occurred at 9:30 a.m. in front of the halfway house at 1430 G St. NE. They said Thomasine Williams, an employe of the finance office of the D.C. jail, and Oscar Murden, a D.C. jail guard, were collecting the money from D.C. custodial institutions and halfway houses for delivery to the D.C. treasurer.

After collecting $208 from the Northeast halfway house, Williams and Murden were approached on the driver side of their D.C. Department of Corrections car by a man wearing a ski mask, officials said.

They said the man put a small caliber pistol to Murden's head, robbed him of his wallet containing $30, and ordered Williams to hand over the blue canvas bag that was used to carry the other money.

The gunman then disappeared into an alley after warning the two officials to stay in the car and not to follow him, police said.

Police said the money came from inmate work earnings and savings, and meals sold to visitors at the D.C. jail.