Orlando terrorist traded texts with wife during massacre

In the midst of the deadliest mass shooting in modern American history, Omar Mateen texted his wife to ask her if she had seen news about the attack at the Pulse nightclub in Orlando.

Mateen and his wife, Noor Salman, exchanged texts while the massacre was still unfolding early Sunday morning -- and at one point, Salman responded saying that she loved him, a law enforcement source close to the investigation confirmed to Fox News.

NBC, citing a source close to Salman, reported that Mateen's mother called Salman at around 2 a.m. Sunday to ask if she knew where Mateen was. Salman responded that she did not. After hanging up, Salman texted Mateen, "Where are you?" at around 2:30 a.m.

Mateen reportedly responded, "Do you see what's happening?" When Salman answered, "No?", Mateen texted back, "I love you, babe."

After that, Salman reportedly told federal investigators that she tried to call Mateen multiple times, but he did not answer. NBC reported that Salman was told details of the attack by local police after they surrounded the house the couple shared in Port St. Lucie.

Mateen was killed in a shootout with police approximately three hours after his attack began. He murdered 49 people and injured 53 others in what President Obama and others have called an act of terrorism.

Earlier this week, it was revealed that Mateen posted a statement to one of his Facebook accounts pledging allegiance to ISIS leader Abu Bakr al-Baghdadi and ranting, "real muslims will never accept the filthy ways of the west ... You kill innocent women and children by doing us airstrikes..now taste the Islamic state vengeance."

Mateen also used his Facebook account to search for media reports about the attack, using keywords like "Pulse Orlando" and "shooting." An FBI source told FoxNews.com he also made 16 phone calls from inside the club. Some of those calls were to 911 operators, to whom he again pledged allegience to ISIS and express admiration for the Boston Marathon bombers.

Fox News' Matt Dean contributed to this report.