Brian Loncar, the prominent North Texas attorney who died just days after his daughter committed suicide, died after an apparent drug overdose, News 8 has learned.

The Dallas County medical examiner said Loncar’s cause of death was “the toxic effect of cocaine.” Secondary causes of hypertension -- abnormally high blood pressure -- and heart disease were also listed.

His manner of death was “accidental," according to the medical examiner.

Loncar was found dead in a car outside his law offices in Dallas on Dec. 4, just two days after the funeral for his 16-year-old daughter, Grace.

• LINKS: Depression treatment in Dallas, Fort Worth

Grace Loncar took her own life on Nov. 25 after bouts with depression. The family first said Brian Loncar had died of a heart attack. In a statement Thursday, the family said it accepts the finding that drugs were involved in Loncar's death, but that he "died of a broken heart." Read the statement below:

“The Dallas County Medical Examiner’s office released a finding that our beloved Brian Loncar’s death was caused by an accidental drug overdose. While we accept this scientific finding, those of us who were closest to him already knew the cause of his death. Brian died of a broken heart.

“Brian’s passing followed his daughter Grace’s death by suicide. These are unimaginable losses for our family. Hopefully, these events will serve as heartbreaking reminders that we all need to reach out and care for our loved ones - every day.

“Our family appreciates the outpouring of support as well as the efforts to give us the privacy and space we need to mourn Brian and Grace. We are prayerful that the community will help us examine ways to prevent these types of tragedies from shattering another home and family.”

Loncar's wife, Sue, started the Grace and Brian Loncar Foundation in the days after Brian's death, to help families battling similar issues of depression and grief.

Loncar, 56, specialized as the lead attorney in a civil litigation law firm. He was billed as “The Strong Arm” in a series of well-known TV commercials that have aired in North Texas for years. Loncar & Associates was founded in 1988, and now has several offices across Texas and serves 7,000 clients per year, according to the firm’s website.