District attorney investigators say a man who died while in Costa Mesa police custody in May 2011 succumbed to natural causes.

A letter to Chief Tom Gazsi from the Orange County district attorney's office released Wednesday said investigators saw no criminal culpability in an officer's actions.

George Marques, 44, of Placentia, was suspected of shoplifting sunglasses from a store in South Coast Plaza on the afternoon of May 18, 2011.

Employees at Saks Fifth Avenue were able to hold Marques facedown on the ground as he tried to flee, but he kept struggling, the report states.

When an officer arrived, he knelt on Marques' back and was able to use two pairs of handcuffs to retrain the large man's arms behind his back, according to the report.

The officer then reportedly pursued a second suspect who had left the scene in a taxi.

Store employees called paramedics when they noticed Marques had stopped breathing. Marques was pronounced dead at Coastal Communities Hospital in Santa Ana at 4:49 p.m., according to the report.

Citing the results of an autopsy, investigators said Marques had a pacemaker, prior coronary bypass surgery, a coronary blockage, an enlarged heart and multiple drugs in his system when he died.

Ultimately, investigators said his death was due to heart disease when his pacemaker was unable to revive him while he was in custody.

There was no sign of head trauma or fractures from the arrest, the report stated.

— Jeremiah Dobruck

Twitter: @jeremiahdobruck