A Texas man has been sentenced to 18 months in federal prison for threatening to assassinate President Trump, prosecutors say.

The suspect, 36-year-old Mickael Gedlu was sentenced Friday, officials with the U.S. attorney’s office in Dallas announced. He pleaded guilty last December to making threats against the president.

According to plea documents, Gedlu admitted he threatened Trump’s life on social media, stating on YouTube: “I am waiting for Trump to visit Dallas before I attempt to assassinate him.”

During the court proceedings, prosecutors said that on May 31, 2018, Gedlu was observed across the street from Dallas’ Adolphus Hotel just 30 minutes before Trump arrived there for a fundraiser.

Dallas police officers noticed that Gedlu was holding a “Kill Trump” sign and arrested him as he screamed “kill the president.”

Prosecutors said the U.S. Secret Service and Dallas Police partnered on the investigation.