Terrance Gainer's decision to resign as the leader of U.S. Capitol Police is "a blow for the entire region," D.C. Police Chief Charles Ramsey said Saturday.

Ramsey called Gainer "an excellent police officer and an excellent police chief." Ramsey was Gainer's boss when Gainer was second-in-command with D.C. police.

Chief Gainer announced his resignation Friday after objections were raised to the hiring of his son-in-law as a police officer.

Gainer, who served for four years as head of the police force in charge of protecting Congress, said his retirement would be effective April 6.

"I've been a policeman now or a military person for the last 38 years," Gainer told a local radio station. "I'm a little bit tired, and I want to try some new things, recharge my batteries and give some other people an opportunity."

In a statement obtained by The Associated Press, Gainer told his officers he did not know he had broken any law when he hired one of his relatives on the police force, but added, "Bottom line -- we just learned -- is that two of us couldn't be on the job."

The 1967 law, known as the nepotism law, was brought to his attention in the past week, Gainer said.

"Why this wasn't known until last Friday is one of those life mysteries, which, for me, aren't worth agonizing," Gainer told his officers.

Gainer's son-in-law, Darren Ohle, who has been with the Capitol Police for 2 1/2 years, also resigned from his post, Gainer said.

While he had no intention of leaving, Gainer said he was considering jobs in the private sector with nonprofit associations.

Aside from working for the Metropolitan Police Department, Gainer is a decorated Vietnam veteran, Chicago homicide detective and lawyer.

The Capitol Police Board issued a statement saying Gainer's "tenure has been characterized by skillful leadership, always in balance with a keen awareness of the crucial and integral role the Capitol Police play."

The Capitol Police are charged with protecting 535 lawmakers and about 200 square blocks in and around the Capitol. The force came under new stress and scrutiny since the Sept. 11 terrorist attacks as new overtime requirements were mandated. Gainer was named chief of the force in 2002 and worked to bolster the agency's size and jurisdiction, while faced with the threat of terrorism.

Rep. Juanita Millender-McDonald, D-Calif., ranking member on the House committee that oversees the police force, praised Gainer's tenure.

"I applaud the chief's work in providing a more diverse workforce and his commitment to promoting women and minorities, and he would be sorely missed," Millender-McDonald said in a statement.

But Gainer has also been criticized by D.C. officials for not coordinating well with the city government on issues such as traffic restrictions imposed on Capitol Hill. A spokeswoman for Del. Eleanor Holmes Norton, D-D.C., said the congresswoman had no comment on Gainer's resignation.