Reginald Robinson Jr., the part-time coach accused of fondling two students last month, was fired by the D.C. school system in 1994 after officials learned of a prior conviction for sex charges. But he later returned to the school system because two principals did not recheck his background, officials said yesterday.

The background check would have turned up a personnel folder stamped "Do Not Rehire," they said, and could have revealed that Robinson had a record and was on an online registry of sex offenders kept by the state of Maryland.

The revelations came at a D.C. Council hearing yesterday during which school officials were questioned about how Robinson, 35, could get a job at two D.C. schools despite pleading guilty in February 2001 to a third-degree sex offense involving a 14-year-old girl in Prince George's County. Robinson, who was put on probation in 2001, also was convicted in 1986 of a sex offense.

D.C. police and school security personnel missed at least one other opportunity to uncover Robinson's background. Last year, they investigated an unrelated allegation that Robinson made sexual advances toward a student. Robinson was cleared, but officials did not discover his criminal record or listing on the Maryland Web site.

"It's apparent . . . that we have had many bites at the apple," D.C. Council member Adrian M. Fenty (D-Ward 4) told school officials. "This is really despicable."

School officials said they require background checks for all employees who deal with children, but that Robinson had slipped through because he was hired by individual schools, which paid him by the season for his work as a coach. Those schools were Fletcher-Johnson Education Center and Ronald H. Brown Middle School.

Superintendent Paul L. Vance said principals have a responsibility to "come down and check" the school system's personnel folders.

Robinson, a track and basketball coach, was arrested at the school system's headquarters on Feb. 3 and charged with two counts of second-degree child sexual abuse. He has pleaded not guilty. According to charging documents, he improperly touched two girls -- ages 13 and 14 -- from Brown Middle School in separate incidents last month. One episode allegedly took place in Robinson's car and the other allegedly happened in the school's gym in the 4800 block of Meade Street NE.

Since Robinson's arrest, two other school employees have been accused of sexually abusing students. School officials said criminal background checks were run on both of them before they were hired.

School officials yesterday said that Robinson first was hired by the system at Roper Junior High School in 1994. A background check was done at that time, and it uncovered a conviction on second- and third-degree child sex offense charges in Maryland in 1986, said Theodore Tuckson, acting head of school security. Because of this conviction, Robinson was fired by the school system on Sept. 6, 1994, four days after he was hired, officials said yesterday.

Robinson, of Fort Washington, began working at Brown in September 2001. It remained unclear yesterday exactly when Robinson was hired at Fletcher-Johnson, a school in the 4600 block of Benning Road SE that has students from pre-kindergarten to ninth grade.

While at Brown, another staff member made the allegation that Robinson was making sexual advances toward a student, officials said yesterday.

Police and school security officials investigated the allegation, Tuckson said, but background checks were not done because they are not required if a complaint was found to be unsubstantiated.

School officials yesterday said they are conducting a review to see if background checks were not performed on other part-time employees. But Fenty and D.C. Council member Kevin P. Chavous (D-Ward 7) said they were unsatisfied.

"One can't help but be left with the question: What else is out there?" Chavous said.

Staff researcher Bobbye Pratt contributed to this report.

Reginald Robinson Jr., who faces sex charges, was hired by D.C. schools without a background check.