U.S. marshals patrol the area outside federal court in Washington in 2014 (Manuel Balce Ceneta/AP)

The departing chairman of the Senate Judiciary Committee on Thursday issued a scathing summary of his years investigating the U.S. Marshals Service, saying his committee found “a culture of mismanagement, abuse of authority and lax accountability” at the law enforcement agency.

“Poor leadership and pervasive misconduct cripples morale and corrodes trust of employees tasked with apprehending criminals and keeping communities safe,” said Sen. Charles E. Grassley (R-Iowa). “This culture must change.”

The memo prepared by Grassley’s staff summarizes the committee’s examination of claims by more than 100 purported whistleblowers who came forward to allege misconduct and mismanagement by senior Marshals Service officials.

It highlights years of alleged misdeeds, from deputy marshals forging hundreds of subpoenas to gather telephone records — a years-long practice that, even when it was discovered, led to no personnel dismissals — to repeated attempts to retaliate against whistleblowers who brought misconduct to light.

A Marshals Service spokesman did not immediately respond to requests for comment.

Investigations by Grassley’s committee and the Justice Department’s inspector general found that the marshals’ leadership, including the agency’s former director, Stacia Hylton, violated federal hiring rules in filling positions at the agency and misspent money.

“The USMS has repeatedly spent taxpayer dollars on lavish and unnecessary items, such as a $22,000 conference table and a speechwriter who received contracts totaling over a million dollars,” the memo says.

“The committee noted a very troubling overall lack of accountability at the USMS,” the memo says, including the decision last year to allow a senior official to retire with full benefits after two inspector-general investigations found he misused government resources, engaged in sexual harassment, and threatened and retaliated against employees who participated in an investigation of his conduct. The official was not identified.

The memo also discloses a long-running practice among deputy marshals in Indiana who more than a decade ago allegedly used hundreds of phony subpoenas to get phone records on people connected to fugitives.

For a 10-year period ending in 2005, “approximately 800 of the fraudulent subpoenas were served on telecommunications providers in order to obtain telephone records of private citizens connected to fugitive investigations,” according to an investigative document released with the senator’s memo. “The subpoenas contained a pre-printed signature” from a judge who later told investigators he never issued the subpoenas and was not even assigned to the court in question after the year 2000.

The inspector general’s investigation could not determine who began the phony-subpoena practice but found it was widespread in that district. A review of Marshals Service subpoenas received by AT&T and related companies over less than a year and a half found 134 fraudulent subpoenas out of a total of 162 documents recovered. One service employee told investigators that he alone used the phony subpoenas approximately 500 times.

No criminal charges were ever filed in the matter, and only one Marshals Service employee was given a reprimand, according to Justice Department officials. Two of the employees who were criticized for their roles in the phony-subpoena practice were later promoted.

The committee and inspector general also found evidence that when senior officials at the agency came under investigation, they responded by trying to ferret out whistleblowers and punish them.