Turkish leader Erdogan focuses on new internal threat: The way he's drawn

But Mr. Kart’s cartoon targeting the corruption investigation, which Mr. Erdogan has characterized as an attempt by a rival Islamic group to overthrow his government, appeared to be the final straw. The investigation, which resulted in the resignations of three ministers, was seen as one of the most serious threats to Mr. Erdogan’s rule in more than a decade.

To many proponents of news media freedom, the legal action against Mr. Kart — he faced nearly 10 years in prison on the charges — was a warning to cartoonists that they were not safe from government retaliation.

“The extension of judicial harassment to caricaturists is indicative of the increasing disregard for the right to freedom of expression in the country,” said Alev Yaman, a researcher on Turkey for PEN International, a London-based media rights organization.

“Turkey has a long and rich tradition of political satire,” Ms. Yaman added. “This case not only represents an attack on free speech but also a betrayal of Turkey’s artistic and democratic heritage.”