Anti-Islamist Jordanian writer Nahed Hattar, charged last month for posting a cartoon deemed offensive to Islam, was shot dead in the capital Amman on Sunday, the country's state news agency Petra reported.
The gunman, who fired three bullets at the 56-year-old journalist outside a courthouse, has been caught by police, Petra reported without giving further details.
The motive for the murder was not immediately clear.
The shooter fired from a close range at Hattar, a witness said.
"The shooting happened from a distance of about 1 metre. The criminal was muttering words in a low voice," the witness, identified as Mohammed al-Ghabeer, told independent Jordanian news website al-Ghad.
"Hattar fell on the ground after receiving the first bullet in the chest. He received more bullets in other parts of the body."
Hattar's shooter had entered Jordan from a neighbouring country the day before the incident and he had been wearing a traditional Jordanian headdress and a long beard at the time of his arrest, al-Ghad reported.
Last month, Hattar, a secular Christian, caused outrage among Jordan's Muslims when he posted an anonymous cartoon on his Facebook page that many deemed blasphemous.
The caricature shows a man in heaven sleeping with two women and asking God to bring drink.
Hattar removed the cartoon shortly thereafter, saying "it mocks terrorists and their concept of God and heaven. It does not infringe God's divinity in any way."
Later, he was arrested and charged with inciting sectarian strife. Early this month, a Jordanian court released him from jail on bail pending his trial.
Hattar was on his way to attend a trial session when he was shot, Jordanian media reported.
The Jordanian government condemned Hattar's killing, calling it a "heinous crime."
"The law will be applied strictly to the one who perpetrated this heinous crime," the government's spokesman, Mohammed al-Moumani, told Petra.
"The government will strike with an iron fist against anyone exploiting this crime to spread hate speech."
Hattar's family said he had previously informed the authorities that he had received deaths threats, but got no protection.
There was no official comment.
Hattar wrote several critiques on political Islamism. He was also known for backing the regime of Syrian President Bashar al-Assad, who is facing a five-year armed rebellion.