U.S. Sen. Charles Grassley said in a letter this week that the family of slain Border Patrol agent Brian Terry "deserves better" than the information provided so far about the guns used to kill Terry.

Grassley, R-Iowa, has been pursuing allegations that the Bureau of Alcohol Tobacco and Firearms allowed a gun smuggler they were investigating to purchase and keep the weapons used in the December shootout in which Terry died.

In a letter sent on Wednesday to U.S. Attorney General Eric Holder,  complained that the response to his Jan. 27 letter containing the allegation has “been little more than delay and denial.”

In the letter, Grassley stood by his assertion that members of the Judiciary Committee had received numerous reports that the ATF sanctioned the sale of three assault rifles in Glendale on Jan. 16, 2010 - two of which were used in a Dec. 14, 2010 gunfight northwest of Nogales that killed Terry.

“The allegations I received are supported by documentation,” Grassley wrote.

He writes that Jaime Avila, arrested on Dec. 15, 2010 in connection with a gun smuggling ring, purchased three AK-47 variant weapons from a gun dealer in Glendale, Ariz. on Jan. 16, 2010. The ATF entered the serial numbers of the three guns in the National Tracing Center’s suspect gun database three days later, Grassley wrote.

The ATF continued tracking Avila’s firearm purchases over the next several months, including two .50 caliber rifles bought in June 2010, Grassley wrote.

The serial numbers of two of the weapons recovered from the scene of the Dec. 14 gunfight matched two of the AK-47 variant weapons purchased on Jan. 16, 2010 in Glendale, Grassley wrote.

“The Terry family deserves answers,” Grassley wrote. “The whistleblowers have expressed a desire to honor agent Terry’s memory by disclosing this information. The Justice Department should work to do the same. The best way to honor his memory is to come clean.”

In a Feb. 4 letter to Grassley, Assistant Attorney General Ronald Weich of the U.S. Department of Justice said the allegation is false.

"ATF makes every effort to interdict weapons that have been purchased illegally and prevent their transportation to Mexico," Weich wrote.

Weich also denied a claim in a Jan. 31 letter from Grassley that an ATF official in Phoenix retaliated against an agent who answered inquiries from Grassley's office.

Grassley also questions what happened to all 769 firearms referenced in the indictment of Avila.

"The indictment refers to the recovery of only about 103 weapons," Grassley wrote. "So, where are the other approximately 666 weapons referenced in the indictment? Why did the ATF not seize them?"

In Grassley’s letter this week, he included an email from Terry’s stepmother, Carolyn Terry:

“It’s hard to accept that our son was shot and murdered with a gun that was bought in the U.S. We have not had any contact from the Border Patrol or any other agents since returning home on the 22nd of (January). Our calls are not returned. I truly feel that our son’s death is a cover-up and they hope that we will go away.”

“That will not happen. We want to know who allowed the sale of the gun that murdered our son. Any help will be appreciated. We are the victims of this case and we want some answers.”

Agent Terry, 40, was killed Dec. 14 during a shootout with suspected border bandits near Peck Canyon northwest of Nogales. Four illegal immigrants from Mexico were arrested that night in the area of the shooting and two more the next day but the U.S. Attorney's Office has not announced any criminal charges in relation to the shooting. FBI spokesman Manuel Johnson said the investigation is ongoing.

Terry, a three-year veteran of the agency, was the 10th agent to die on duty in the Border Patrol Tucson Sector since 1926 and the first agent shot to death since 1998.

Asked about the investigation into Terry's death during a news conference on Tuesday, Customs and Border Protection commissioner Alan Bersin declined to comment, citing the ongoing FBI investigation. He said he and others from the agency have been in contact with the family and will continue to support them.

“They will have the support of Customs and Border Protection forever and they are being briefed in a confidential way by the United States Attorney’s Office and the FBI as matters develop,” Bersin said.

Contact reporter Brady McCombs at 573-4213 or bmccombs@azstarnet.com.