New details have emerged about interactions between Omar Mateen and his wife on the night he killed 49 people and wounded 53 others at an Orlando nightclub.

An official familiar with the timeline told CBS News that Mateen was active on social media before and during the rampage.

Records show that prior to the shooting, Mateen posted on Facebook "Alliance to [ISIS leader] Abu Bakr Al Baghdadi," CBS News correspondent Jeff Pegues reported.

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Then after the gunfire began, Mateen paused. Sources told CBS News he searched for "Pulse Orlando" and "shooting," perhaps to see if the massacre was trending online.

He also made calls to 911 and to a television station about the ongoing shooting.

A law enforcement source told CBS News senior investigative producer Pat Milton that during the shooting, Mateen was also communicating with his wife via text message. The source said the couple exchanged, "I love you."

Investigators are focusing on what role Mateen's wife, Noor Salman, might have played in the attack. She has been cooperating, but officials believe she had some knowledge of an attack and will likely face some charges.

Law enforcement sources said Salman purchased ammunition with her husband, and they believe she drove with him as he cased the Pulse nightclub prior to the shooting.

Milton reported at this point in the investigation, it appears there is insufficient evidence to bring the more serious charge of conspiracy, according to a law enforcement source.

Investigators are also looking at other family members to determine what, if anything, that they may known about the attack and any financial support Mateen received from his family, including his father.

School records show that Mateen was a troubled child and a disciplinary problem going back to the third grade.