Chicago (CBS) — Susan Jones listened to the 911 call for the first time this week. It’s the call her ex-husband and former Porter County Sheriff’s Officer Curtis R. Jones made the night of July 24, 2016, when investigators said he inflicted significant brain damage on his then six-month-old son Brax.

Curtis Jones’ cold, conversational demeanor terrified Brax’s mom.

“In the background, you can hear my son breathing, dying,” Susan Jones said. “He was having atonal breathing.”

The video recording of the 911 call has been viewed more than 20,000 times just this week. Brax survived but battles a significant brain injury. He’s one of about 1,300 shaken baby syndrome cases reported in the U.S. each year.

Susan Jones said justice for kids like Brax is not always swift.

“He was nothing but perfectly healthy, and he did not deserve this,” Jones said.

Curtis Jones was charged with three felony counts. He’s been out on bond and living out of state since April 2017. The Porter County Sheriff’s Department confirmed his employment up until 2005 but declined to comment for this story.

The case has been slow going. A jury trial set for October was cancelled and rescheduled for early next year.

Meanwhile, Susan Jones wants to bring awareness to this case and others like it. She offered advice for anyone who may be frustrated while handling an infant.

“Put the baby down in the crib in a safe place, walk away, take a five-minute breather and walk away. Try it again,” she said.

Curtis Jones’ attorney told me Brax’s mom is trying to “vilify” his client, who denies that he did anything wrong.

The Porter County Prosecutor’s Office did not return CBS 2’s request for comment.