Dr. Raynaldo Rivera Ortiz Jr., 59, made his first appearance in federal court Friday.

Dressed in shorts and a polo dress shirt, the Dallas anesthesiologist was asked by Magistrate Judge Renee H. Toliver if he understood the charges being brought against him and if he knew his constitutional rights.

He said, “Yes, ma’am.”

Ortiz is accused of spiking IV bags with drugs that allegedly led to the death of at least one person and the injury of many others, as reported by The Dallas Express. He was arrested on Wednesday.

The Texas Medical Board suspended his license last Friday, reasoning that he posed “a continuing threat to public welfare.”

Federal investigators claim there is evidence that Ortiz tampered with IV bags at the Baylor Scott & White Surgicare in North Dallas, where he worked.

The Dallas Express first broke the connection between Ortiz and the medical facility on September 2.

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The tampered bags were subsequently administered to patients. Each time Ortiz allegedly tampered with an IV bag, the patient would suffer a medical emergency during or after their procedure.

In June, a fellow anesthesiologist, Melanie Kaspar, died after self-administering an IV bag she took home from the facility. She was initially presumed to have suffered a heart attack.

However, an autopsy revealed that she died from a lethal dose of bupivacaine, a local anesthetic often administered as an epidural injection into the spinal column to produce numbness during labor or certain surgeries.

“I grappled with the fact she had a heart attack because she was a very healthy woman, she would sit on her bicycle training for hours and not have any issues,” said John Kaspar, Melanie’s husband, speaking with The Dallas Express.

“I think knowing that something else was the cause of it was a little easier to swallow, from the sheer fact that it wasn’t an illness,” he said.

Still, the moment continues to haunt the widower. They had been married for 30 years.

“I was a firsthand witness to her demise. It is the most agonizing thing I’ve ever seen in my entire life,” he said. “I’ve got that to struggle with for a long time.”

Melanie Kaspar was not the only victim who allegedly suffered at Ortiz’s hands.

On August 24, a young man reportedly underwent surgery at the Surgicare center and experienced a life-threatening medical emergency after an IV, presumed to be tampered with by Ortiz, had been administered.

The surgery center identified at least 10 other similar incidents in the past few months.

In addition to his license suspension, Ortiz has a history of disciplinary actions against him by the Texas Medical Board and a criminal history of cruelty to animals and assault charges. Furthermore, the IRS claimed he owed more than $4 million in unpaid taxes.

Ortiz is due back in court for a preliminary hearing on Monday at 10 a.m.

If convicted, he could face up to life in prison.

For more Dallas crime-related news, see how Dallas City Councilmember Chad West of District 1 was named The Dallas Express’ Crime Boss of the Month for June 2022.