US police have arrested a 46-year-old man in connection with the deaths of two police officers in the state of Iowa.
The officers were shot and killed in separate "ambush-style attacks" as they sat in their patrol cars.
Scott Michael Greene from Urbandale, a suburb of state capital Des Moines, was captured less than two hours after police released his name and said they were searching for him.
They had cautioned that he should be considered armed and dangerous.
"We think he's got some information that's pretty critical to us closing this case out. We can't go into great detail right now. But, he's definitely somebody that we want to talk to," Des Moines police department spokesman Paul Parizek told a news conference.
One officer was found dead about 1am local time in Urbandale. The second officer was found dead about 1.30am local time in the city, NBC News reported.
Mr Parizek said: "It doesn't look like there was any interaction between these officers, and whoever the coward is ... shot them as they sat in their cars."
He said police would be doubling up to patrol in pairs in the wake of the shootings.
"There is a clear and present danger to police officers right now and we've doubled up our police officers so that no one is working alone," he said.
A series of tips and leads drew investigators to Greene, the officers said, although they declined to comment on a motive for the killings.
The incident marks the first time a Des Moines officer has been shot in the line of duty since two police were killed in 1977, The Des Moines Register said.
Officers in the cities of Dallas and Baton Rouge, Louisiana, were the targets of deadly ambushes earlier this year after police killed two black men in separate incidents in a Minnesota suburb and Baton Rouge.
Philadelphia police officers have been deliberately targeted by a gunman twice this year.
Before the shootings in Iowa, 50 police officers had died by gunfire, two accidentally, in the line of duty in the US this year, according to the Officer Down Memorial Page website.
