Security forces have detained Tevfik Mutlu, who is being charged for links to the Gülenist Terror Group (FETÖ), as he was trying to flee to Georgia.
Authorities discovered he was a user of ByLock, an encrypted messaging app exclusively used by the terrorist group, and he had visited the group's leader Fetullah Gülen - in Pennsylvania, United States.
Mutlu's brother Seçkin Mutlu, a police chief, was imprisoned earlier for his links to FETÖ. Security sources are investigating if Tevfik Mutlu, like Metin Topuz, carried out espionage for FETÖ.
FETÖ, among other crimes, is accused of masterminding and carrying out a failed coup attempt in July 2016, which left 249 people dead and hundreds of others injured.
After the attempt was quelled thanks to strong public resistance, security forces have detained and/or arrested thousands of suspects in a renewed crackdown on the terrorist group, which has been under the spotlight since it tried to seize power twice in 2013 through its infiltrators in the judiciary and law enforcement.
The United States, a NATO ally of Turkey, frequently comes up in FETÖ-linked investigations. The U.S. has been a hot spot for fugitive members of the group who are trying to flee from terror charges in Turkey. The U.S. is being criticized for tolerating the group and for its reluctance in extraditing Gülen.
Metin Topuz's arrest sparked a visa crisis, which Ankara claims is the work of outgoing U.S. Ambassador John Bass. After the arrest, the United States suspended visa services with Turkey and Turkey retaliated accordingly.
Topuz is charged with espionage and violating constitutional order - a terrorism charge. Prosecutors say he had phone contacts with FETÖ members and often held talks with several FETÖ police chiefs who were arrested after the 2013 coup attempts.
"The suspect acted as a liaison between members of FETÖ and its leader, Fetullah Gülen," an indictment against Topuz reads.
On a different note, Turkey is also accusing the United States of harboring a suspect linked to the PKK, another terrorist group. In February, police detained Hamza Uluçay, a Turkish man working as an interpreter for the U.S. Consulate in Adana, for his links to the PKK.
Uluçay, a longtime employee of the U.S. Consulate in the city of Adana, is accused of "inciting the public to rally" after the shooting of a senior PKK militant in anti-terror operations.