Washington ? The Justice Department asked Congress this week for authority to block suspected terrorists from buying handguns and explosives.

Sen. Frank Lautenberg, D-N.J., asked what took so long.

He introduced the bill sought by the department on Thursday and noted that he had raised questions about “the terror gap in our gun laws” more than two years ago.

That was when the Government Accountability Office delivered a report requested by Lautenberg and Sen. Joseph Biden, D-Del., showing that 35 out of 44 attempted gun purchases by people on terror watch lists were cleared after background checks during a five-month period in 2004.

Under current law, a purchase cannot be denied solely because someone is on a list as a known or suspected terrorist or supporter of terrorism. Rather, the prospective purchaser must have some other disqualification, such as a felony conviction or illegal immigrant status.

Procedures implemented in 2004 allowed for “instant” background checks to be delayed up to three days to give federal agents more time to find potentially disqualifying information. But if none were found, the purchase was cleared.

“It took years, but the administration finally realized that letting terrorists buy guns is dangerous,” said Lautenberg, who also sponsored the federal law barring those convicted of domestic-violence offenses from buying guns.

A Justice spokesman said the department moved as quickly as possible to address concerns Lautenberg raised in letters to Attorney General Alberto Gonzales and FBI Director Robert Mueller in February 2005.