AUSTIN (KXAN) — Two suspects linked to the beating death of Austinite Bakari Henderson in Greece over the summer have fled to their native country of Serbia, according to a letter sent to Secretary of State Rex Tillerson from U.S. Senators John Cornyn and Ted Cruz and Congressman Michael McCaul, R-Austin.

In the letter dated Oct. 31, the Texas lawmakers are urging Tillerson to utilize “all diplomatic means available to ensure that the aggressors do not escape justice.”

Henderson, 22, was killed on July 7 while vacationing on the Greek island of Zakynthos. Surveillance video reportedly showed several men tackle Henderson and push him into a parked car. Over the next 10-20 seconds, numerous men can be seen punching him and kicking him while he was on the ground. Greek authorities said Henderson suffered multiple hits and died from severe blows to the head.

Within a few days after Henderson’s death, nine Serbian men were charged in connection with his death. The letter states while there have been multiple arrests, there are “at least two suspects” who have fled back to Serbia.

In closing, the lawmakers are asking for Tillerson’s “prompt attention to this issue.”