Donald Trump Jr. has been officially served with court papers in a lawsuit brought by former Lt. Col. Alexander Vindman for witness intimidation and retaliation.

Vindman announced earlier this month that he is also suing Rudy Giuliani, former White House Deputy Chief of Staff Dan Scavino and former Trump White House official Julia Hahn.

Vindman has accused the defendants of "an intentional, concerted campaign of unlawful intimidation and retaliation" in connection to his role in the first impeachment of then-President Donald Trump.