Threats to federal judges and prosecutors have jumped dramatically, according to a new government report issued Monday that found such threats more than doubled in the past six years.

By coincidence, the report was issued shortly before a gunman walked into a federal building in Las Vegas and opened fire, killing a court security officer and seriously wounding a deputy U.S. marshal. The suspect was shot dead by other officers, and the motive for the attack wasn't immediately clear.

The report by Justice Department Inspector General Glenn Fine concluded there are still major gaps in reporting and responding to threats. Concerns about security for judges intensified five years ago after the husband and mother of a federal judge in Chicago were killed by a man angry over a court ruling.

Between 2003 and 2008, the number of threats and inappropriate communications jumped from 592 to 1,278, the report found. The government defines "inappropriate communications" as messages that aren't explicitly threatening but worrisome enough to require further investigation.

The federal court system has more than 2,000 judges and more than 5,000 prosecutors.

Prosecutors and judges "do not consistently and promptly report threats they receive," the inspector general's report found — estimating that as many as 25 percent of threats are not reported to security officials.

When those threats are reported, the U.S. Marshals do not consistently coordinate with local police, and in many cases don't record ever having notified the FBI of the threats.

According to the marshals' own threat database, there was no record of having notified the FBI of 40 percent of the threats, the report said.

The U.S. Marshals Service agreed with the inspector general's recommendations to improve coordination with local and FBI officials, and to more thoroughly analyze each threat and take necessary protective measures.

Marshals spokesman Jeff Carter said the agency has "made great strides over the past few years in our judicial security mission, and as the U.S. Marshals Service believes there is always room to perfect the process, we will carry out the report's recommendations with that goal in mind."

Justice Department spokeswoman Melissa Schwartz said the agency is carefully examining the findings and "will take appropriate action to ensure the safety of all employees in the United States Attorneys' offices."

The review notes that no federal judges or prosecutors have been killed in the six year period. The security of judges and their families has been a growing concern since the 2005 slaying of Judge Joan Humphrey Lefkow's mother and husband. Investigators determined the killer was angry that the judge had dismissed his medical malpractice lawsuit.