Brennaman recounted one instance when she got a speeding ticket and Devin Kelley pulled a gun out of his holster, pointed it at her and asked, "Do you want to die? Do you want to die?' "
"He just had a lot of demons or hatred inside of him," she told the television show, according to a clip that aired Friday on "CBS Evening News." The full interview is set to appear Monday on "Inside Edition."
Public records show that Devin Kelley married Tessa in 2011 and they divorced in 2012.
Devin Kelley served in logistics readiness at Holloman Air Force Base in New Mexico from 2010 until his discharge for assaulting his then-wife and stepson.
Devin Kelley initially faced multiple charges, according to military records. They included assault and battery against his spouse, aggravated assault against his stepson and four charges involving firearms, including two of pointing a loaded firearm at his wife and two of pointing an unloaded firearm.
Military prosecutors dropped the firearms charges before trial in an agreement in which Devin Kelley pleaded guilty to aggravated assault against the child and assault against his wife.
As part of his plea, Devin Kelley admitted to hitting his stepson on the head and body "with a force likely to produce death or grievous bodily harm."
Devin Kelley also admitted to hitting his then-wife, kicking her, choking her and pulling her hair.
The Air Force did not provide a date of the discharge, but his military record indicates he left the service in May 2014.
The Air Force acknowledged it did not relay the killer's court-martial conviction for domestic assault to civilian law enforcement.
The failure to relay the information prevented the entry of his conviction into the federal database that must be checked before someone is able to purchase a firearm. If his information had been in the database, it may have prevented gun sales to Devin Kelley.