Jonathan Crews was 27 years old when he died of a gunshot wound to the chest on February 2, 2014.

The urgent care director from Coppell, Texas, was with his girlfriend Brenda Lazaro in his apartment on that Super Bowl Sunday when she claims he shot himself in the heart.

According to ABC News, Lazoro, 26, called 911 to report that Jonathan had shot himself, after promising that he would “prove his love for her.”

She reportedly admitted that she and Jonathan had been fighting earlier in the day, but told the 911 dispatcher that the argument had calmed down.

“We were just having a discussion and we were just talking,” Lazaro reportedly told the operator. “He just said that he loved me and I didn’t need to leave him and … he said that he was going to prove that he loved me.”

Earlier that same day, Jonathan reportedly had lunch with two close friends, Emily and Jacob Ramsey. Though Emily and Jacob are married, Brenda was jealous of her friendship with Jonathan, and Emily is believed to have been a regular source of conflict in Brenda and Jonathan’s relationship since the time the friends hugged each other in front of Brenda.

Emily Ramsey told ABC News that she, Jacob and Jonathan discussed the conflict at their lunch that Sunday afternoon, and Jonathan was telling them how Brenda was threatened by his friendship with Emily when his girlfriend called him, and asked to speak to Emily.

“She just started yelling at me and telling me that I was a disrespectful little girl. …’You hug my man, that’s so rude,'” Emily says in an upcoming 20/20 segment about Crews’ death, airing Friday night.

Emily says she got a strange text message from Jonathan the night he died: It said “I want to die.” Emily and Crews’ family now believe that Brenda sent the text message to cover her tracks.

The medical examiner reportedly ruled that Jonathan’s cause of death was “undetermined,” and police have said there is not enough evidence to charge Brenda or anyone with the young man’s death.

Crews’ family has filed a civil suit against their son’s former girlfriend, who is now married with a child. The civil trial is expected to begin in September.

20/20 will tell Jonathan’s story on Friday night at 9 p.m. ET. Watch a preview here:

Photo: Family handout