Illinois Senator Tammy Duckworth sent another letter to the Inspector General of the U.S. Department of Homeland Security Friday, saying there is not enough urgency in honoring her request for an investigation into use of force by federal immigration agents in Chicago.

Duckworth sent her initial letter on Oct 17, calling for federal government watchdogs to launch an investigation into immigration agents' tactics in the Chicago area as part of Operation Midway Blitz.

In this second letter, Duckworth notes that since she first requested the probe, "a Federal District Court has determined that DHS use of force under Operation Midway Blitz 'shocks the conscience' and violated a prior Federal court order."

She also highlights Border Patrol Commander Gregory Bovino's admission he lied about being hit by a rock before deploying tear gas during a clash with protester in Little Village, which U.S. District Judge Sara Ellis discussed in court Thursday morning.

"Simply put, DHS is operating like an agency that believes it is unaccountable to the public and above the law," Duckworth writes.

Duckworth also asks the DHS Office of the Inspector General "immediately issue a preservation order requiring DHS to cease and disclose any destruction or alteration of records, documents or data" relevant to any investigation.

She writes that DHS spokespersons have responded to questions with "false narratives that are nearly always subsequently contradicted by camera footage of the incidents in question" and says their "pattern and practice of releasing dishonest and misleading statements that contradict facts on the ground calls into the question the veracity of any DHS incident accounts where camera footage is unavailable."

Judge Ellis issued a preliminary injunction against federal immigration agents over their use of force during Operation Midway Blitz Thursday, strictly curbing the allowed use of force against protesters, journalists and clergy members who are opposing immigration enforcement operations. She also denied the government's request for a stay on the injunction pending appeal.

Read Sen. Duckworth's full letter below.