In the wake of Devin Kelley’s murderous rampage at a tiny church in Texas last month — where the weapon used was a gun Kelley never should have had — USA Today conducted a review and found that federal agents attempted to seize over 4,000 guns from people that failed background checks last year.

A USA TODAY review found that the FBI issued more than 4,000 requests last year for agents from the Bureau of Alcohol Tobacco Firearms and Explosives to retrieve guns from prohibited buyers.

It’s the largest number of such retrieval requests in 10 years, according to bureau records – an especially striking statistic after revelations that a breakdown in the background check system allowed a troubled Air Force veteran to buy a rifle later used to kill 26 worshipers at a Texas church last month.

The FBI’s National Instant Criminal Background Check System (NICS) vets millions of gun purchase transactions every year. But the thousands of gun seizure requests highlight persistent problems in a system where analysts must complete background checks within three days of the proposed purchase. If the background check is not complete within the 72-hour time limit, federal law allows the sale to go forward. ATF agents are asked to take back the guns if the FBI later finds these sales should have been denied.

Although there was no clear statistic concerning how many of the erroneously issued firearms were confiscated by federal authorities, the increase in requests for retrieval are interesting in light of a recent call by Attorney General Jeff Sessions for a comprehensive review of the vetting system following Kelley’s rampage. From a memo issued by Sessions’ office:

The recent tragedy in Sutherland Springs, Texas has revealed that the U.S. Air Force and other military branches may not be fully reporting relevant information to NICS. This is an alarming revelation that must be addressed. Accordingly, I am directing the Federal Bureau of Investigation (FBI) and the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) to take the following actions:

(1)  Work with the Department of Defense to identify and resolve any issues with the military’s reporting of convictions and other information relevant to determining prohibited person status under 18 U.S.C. § 922(g).

(2)  Conduct a review to identify other federal entities that are not fully and accurately reporting information to NICS. Ifany such entities are identified, a plan should be developed to ensure full and accurate reporting to NICS going forward to the extent required under cuJTent law.

(3)  Conduct a review of the format, structure, and wording of ATF Form 4473 and recommend changes as necessary.

(4)  Prepare a report that addresses: (a) the number ofcurrent open investigations for making a false statement on ATF Form 4473; (b) the number of investigations for making a false statement on ATF Form 4473 for the past five years; (c) the prosecution referral and declination numbers for the current year, as well as the past five years for making a false statement on ATF Form 4473; and (d) the priority level assigned to investigations for making a false statement on A TF Form 447

(5) Identify any additional measures that should be taken to prevent firearms from being obtained by prohibited persons, including identifying obstacles to state, local, and tribal entities sharing information with NICS.

There were 27.5 million background checks conducted last year, with 200,000 on Black Friday 2017 alone (a record for a single day). More than 90% of those checks are completed within the 3-day waiting period.