D.C. police, acting on a tip received the day a reward was announced, arrested two Southwest men yesterday and charged them in the death of a Gallaudet College professor who was fatally shot during a robbery in his Southwest apartment building.

The professor, Gerald Adler, 56 who was deaf, was found the evening of Dec. 26, alongside his car in the basement garge of his high-rise building at 560 N St. SW.

He had been shot once in the head by robbers who escaped with about $20. Police theorized that he might have been shot after he failed because of his deafness to respond to a demand for money.

On Jan. 18, it was announced that Adler's neighbors at the Harbor Square complex had offered a $5,000 reward for an arrest and conviction in the case. On that day police heard from an informant, who according to court papers, said he had been told of a fatal shooting.

According to the papers, the informant asserted that two men told him they had shot a man in a garage and had taken $17 from him. The men also reportedly showed the informant a revolver they said had been used.

In addition, police said the informant also selected two photographs from among a number shown him.

Police said Jeffery A. Greenfield, 24, of 200 I St. SW, listed as a construction worker, was arrested at 5 a.m. at 4311 3d St. SE.

They said Larry D. Brown, 25 of 907 Delaware Ave. SW, listed as a printer, was arrested at his address at 4:30 a.m. Both were charged with felony murder.

The suspects appeared yesterday in D.C. Superior Court and were ordered held without bond for five days.

Authorities said Brown was on probation in connection with a charge of receiving stolen property. They said Greenfield was on parole in connection with a first-degree burglary charge.