Veterinarian Rolando homicide
Clark Kelly. Photo credit: Screen shot, CBS8.com

A man was sentenced Tuesday after pleading guilty to involuntary manslaughter for reportedly causing an 88-year-old veterinarian’s fatal heart attack at the victim’s Rolando clinic.

Patrick O’Brien, 39, who has been in custody since Clark Kelly’s death on June 15, 2022, is expected to be released early next month, then serve the remainder of his four-year sentence on mandatory supervision.

O’Brien, 39, was initially charged with murder for the death of the longtime veterinarian at Boulevard Animal Clinic on El Cajon Boulevard.

However, while Kelly was found inside the clinic with a significant head wound, San Diego County’s chief medical examiner testified at a preliminary hearing last year that Kelly died of a stress-induced heart attack, then likely fell and struck the floor or a desk.

Prosecutors argued O’Brien tried to break into the clinic, startling Kelly in the process, while O’Brien’s defense attorney argued there wasn’t enough evidence to show O’Brien ever entered the building.

Kelly made a 911 call at the time and told a dispatcher, “There’s an intruder who’s broken into the clinic.”

Kelly’s wife also ran to a nearby business and told bystanders a man was “trying to break into our place,” according to preliminary hearing testimony.

Kelly was found on the floor of the clinic in a pool of blood, with his cell phone nearby and the dispatcher on the line.

Witnesses pointed O’Brien out to officers. He was spotted sitting near a trash bin about 30 feet from the clinic and was arrested.

At his sentencing hearing, one of Clark’s daughters, Karen Kelly, said her father’s death forced the closure of the clinic after around 60 years of operation.

She called her father “my hero” and “a legend in San Diego” and told O’Brien, “You caused him a painful, horrific death, where he suffered and he couldn’t breathe.”

O’Brien’s defense attorney, Peter Will, reiterated his arguments from the preliminary hearing that there was no evidence that O’Brien touched Kelly or entered the clinic.

“This information undermined the initial conclusions that the system hastily arrived at,” according to Will, who said his client is “genuinely heartbroken about any sadness he has caused the victim’s family.”

Will said that on the day of Kelly’s death, O’Brien was battling serious mental health and drug issues, as well as an infected wound in his leg after being stabbed days earlier.

The attorney said that on June 15, O’Brien entered the courtyard of the clinic but did not enter the clinic itself.

“It appears Mr O’Brien’s presence alone frightened Mr. Kelly such that he called 911 and collapsed while on the phone,” said Will, who also said Kelly had a litany of heart-related health issues.

City News Service contributed to this report.