The outpouring of grief was swift when a local autism doctor was found dead last month in a North Carolina river. The questions quickly followed.

Five days after Jeff Bradstreet, 60, was found submerged in the water with a gunshot wound to his chest, family members started an online fundraiser to to raise money to investigate his death, including the possibility that he was killed.

Police, on the other hand, say the fatal shot was self-inflicted.

Bradstreet’s death came days after his Buford office was searched by the Food and Drug Administration, which was looking for substances Bradstreet used in some of his treatments.

Two weeks after the fundraiser was established, more than 500 people had donated upwards of $31,000 to the cause. Comments on the site and on a memorial Facebook page tell stories of his impact on patients and pray for the family to find the truth.

“We feel there are still serious questions in regard to the cause of death,” said Bob Reeves, Bradstreet’s lawyer.

Bradstreet was found by a fisherman in the Rocky Broad River near Lake Lure, N.C., about 30 miles southeast of Asheville, on June 19. Lt. Jamie Keever, the lead detective on the case with the Rutherford County Sheriff’s Office, said the gun that was used in the shooting was found nearby.

Bradstreet had checked into a hotel earlier that morning, but the room was not ready when he arrived and he never went back for the key. He had suitcases full of clothes in his car, Keever said. The case remains open while the autopsy is pending, but Keever said he would not expect anything to change in his department’s assessment.

“Everything is what it appears to be,” he said. “It’s a self-inflicted gunshot wound to the chest.”

Bradstreet was revered by patients, who came to see him from around the world. His treatment methods were sometimes atypical. In contrast to behavioral therapies that many autism specialists prescribe, Bradstreet used some that are outside the mainstream.

He participated in research including doing tests on the effectiveness of a vitamin D binding protein called Globulin component Macrophage Activating Factor, or GcMAF, which was used in Europe to treat immune problems and cancer. He co-authored at least two papers on GcMAF as an autism treatment.

Tia Severino, the mother of one patient, called his work cutting edge.

David Noakes, the CEO of the English biotech company that provided GcMAF — who was himself raided in January — said he believes Bradstreet was murdered because his insistence that mercury in the vaccine for measles, mumps and rubella causes autism was a threat to drug companies.

“Dr. Bradstreet was the world’s most successful autism doctor, which was one of the reasons he’s now dead,” Noakes said. “He was a lovely man, had a very gentle approach. It’s a great loss.”

A search warrant for Bradstreet’s office released by the U.S. Attorney’s Office Thursday shows the FDA was looking for GcMAF or “any other products or component substances thereof that constitute misbranded drugs” and related records. Neither the U.S. Attorney’s Office or the FDA would comment further on the investigation.

Alycia Halladay, chief science officer of the Autism Science Foundation, said while behavioral interventions have shown broad success, she has not seen proof that there are medical treatments, including GcMAF, that would affect a broad number of autistic patients. She said science has not proven that there are treatments for autism that target the immune system.

“Parents are desperate to try to unlock their child,” she said “They’ll go to whatever extremes they can.”

The vaccine theory, she said, has been scientifically studied and rejected.

While Halladay said she may not have agreed with Bradstreet’s methods, she respected the reputation he had as a caring doctor.

Severino, a Tucker resident whose 8-year-old autistic son had been treated by Bradstreet for 20 months before Bradstreet’s death, called Bradstreet “a really special person” and said he was a hero to her and many others. She described a doctor who would answer text messages on weekends, and who was generous, gentle and effective.

“My son has a chance now, because of Dr. Bradstreet,” she said. “He took him from being locked in his own little world to now he wants to play with the neighbor’s kids… We’re all shocked, and kind of hurting.”