NATIONAL

Omar Mateen was reportedly “cool and calm” after killing 49 people and negotiating with police Sunday at the Pulse nightclub.

Over 50 law enforcement officials were searching the Seven Seas Lagoon at the resort in Orlando, Florida.

Nearly 400 scientists have signed a letter asking President Barack Obama to leave the Arctic Ocean out of a proposed oil and federal gas leasing program.

The U.S. Department of Justice charged a software developer, purportedly a former IBM employee, “with economic espionage and theft of trade secrets” Tuesday.

Russian spies also targeted the networks of Trump and Hillary Clinton, as well as the computers of some Republican PACs, U.S. officials told a newspaper.

Prosecutors said they lacked confidence that Judge Aaron Persky, the judge in the Stanford sexual assault case, could “fairly participate” in a separate such case.

The planned White House meeting is certain to anger China, which considers the exiled Tibetan Buddhist spiritual leader a dangerous separatist.

A federal grand jury has been convened and could charge Omar Mateen's wife, Noor Salman, as early as Wednesday, a source told Reuters.

Noor Mateen admitted driving her husband to sites that he was considering attacking, and was with him when he bought ammunition, a report said.

Later, at a rally in North Carolina, the Republican focused his ire on Hillary Clinton, the presumptive Democrat presidential nominee.

Using labels like "radical Islamic terrorism" to refer to threats won't help end the problem, the president said Tuesday.

A survivor from Sunday’s shooting, Angel Colon, called the gunman “heartless” and “ruthless” on Tuesday as he recounted his experience.

Noor Zahi Salman reportedly said she tried to talk him out of the massacre and drove him to the Pulse nightclub to case the location.

Democratic lawmakers in the House are calling, again, for gun control in the wake of Sunday’s Orlando gay nightclub shooting.

Hillary Clinton has narrowed GOP rival Donald Trump's lead among white and male voters.

Following Clinton’s victory in Tuesday’s District of Columbia primary, the candidates met at a hotel and reportedly agreed to work together to defeat Donald Trump.

It may come as no surprise, but weed sales in Colorado and Washington this year surged on the stoner's holiday.

The Post is the latest news outlet to have its press credentials revoked by the presumptive GOP nominee after the Daily Beast, Politico, BuzzFeed and others.

Candidates have talked about reversing a trend that has seen average weekly expenses rise 170 percent from 1985 to 2011. But parents and advocates say the issue needs more attention.

The shooting at a gay nightclub in Orlando that left 49 dead and 53 wounded has this in common with other mass killings: the AR-15.

Bernie Sanders’ $200 million campaign was a boon for the left-wing consultants who have been honing their digital fundraising and organizing tools for a decade.

President Barack Obama said there was no clear evidence that showed 29-year-old Omar Mateen was directed by external parties.

Orlando is home to Walt Disney World where Omar Mateen, the gunman behind Sunday’s massacre, allegedly scouted locations for a potential attack.

Bernie Sanders said he will meet rival Hillary Clinton to understand her policies if she becomes president.

Officials in Florida have almost completed the grim task of notifying families about the 49 people killed during the Pulse gay nightclub shooting.

Republican U.S. presidential candidate Donald Trump has ratcheted up his campaign rhetoric to include children of immigrants, like himself.

After the Orlando shooting, the call for blood donations underscores a broader imbalance in the world’s supply.

Four Democratic senators called for immediate passage of a bill preventing people on “terror watch lists” from buying firearms or explosives.

The conclusion narrows the already slim chances that President Obama can fulfill his pledge to close the notorious offshore prison.