No employees were harmed in the suspected shooting at the newspaper's offices.
The ACLU said Heyman's arrest constituted "a blatant attempt to chill an independent, free press."
There were 259 journalists in jail by the end of 2016, according to the Committee to Protect Journalists.
Ahmed Abba spent two years in detention before he was convicted.
Gabriele Del Grande has gone on hunger strike to protest his detention.
Islamist militants groups are responsible for many of the journalist killings, said the Committee to Protect Journalists.
"Just because you're a journalist you are not exempted from assassination if you're a son of a bitch," Duterte said.
Nearly 50 journalists are in prison in China, according to the Committee to Protect Journalists.
Donald Trump appeared at a rally in Radford, Virginia, on Monday.
The far-reaching directive, which covers news, gaming and entertainment, starts next month.
This week's anniversary cover features a bloodied God and a message: The killer is still out there.
Four secular bloggers and one publisher were killed in violent attacks this year.
Nearly 70 journalists were killed on the job this year.
The number of jailed journalists in Turkey has doubled in a year.
Russian voters were more concerned about the state of their democracy during the presidency of Dmitry Medvedev than now.
The Washington Post journalist is being held in Tehran's Evin Prison.
Alexandrani has written critical stories of the Egyptian government's action in Sinai.
The arrests of Iranian journalists and businessmen have sent chills through Tehran.
The Al Jazeera journalists are accused of spreading false reports and supporting the Muslim Brotherhood.
Rights advocates say their arrest was part of a crackdown on free speech.