Salt Lake County prosecutors on Friday dismissed charges against a man accused of starting a July Fourth grass fire, saying Cottonwood Heights police made glaring errors in their investigation of the case.

Richard Otterstrom, 49, had been charged in 3rd District Court with reckless burning, a misdemeanor, for setting off aerial fireworks that started the blaze in a large field near his home. The fire scorched about 25 acres, and damaged structures including a home near 3400 E. Banbury Road (7420 South). 

But while Otterstrom was lighting fireworks on Independence Day, he wasn’t in a restricted zone that bans fireworks, as police had relayed to prosecutors, Salt Lake County District Attorney Sim Gill told The Salt Lake Tribune on Friday.

In fact, Otterstrom wasn’t even close. Police initially told prosecutors his home was about 175 feet from the field, well within a 300-foot area where fireworks are banned. Yet it turned out the residence was more than 900 feet from where the blaze broke out, in a zone where fireworks are legal, Gill said.

Otterstrom’s attorney, Nathan Crane, said Friday it was “physically impossible” for his client to have started the blaze.

In addition, police at first told prosecutors that Otterstrom’s home was the only residence in the area that showed evidence of aerial fireworks. 

But that wasn’t true either, according to Gill and Crane. 

Crane said he interviewed neighbors, near 3400 E. Enchanted Hills Drive (7510 South), and “we were able to pinpoint where fireworks were being lit off in that neighborhood, and the neighborhood behind the field.”

Crane said he confirmed that two other groups of people were lighting fireworks within about 20 yards to 25 yards from where the blaze started. 

“It was a severely deficient investigation by the police,” Crane said.

Cottonwood Heights Lt. Dan Bartlett defended his department’s investigation. He said police determined that Otterstrom was the only one shooting off very large aerial fireworks — reaching about 150 feet into the air — while those closer to the blaze were igniting 15-footers.

Police believe, despite Otterstrom’s distance from the field, that sparks from such a large firework, combined with a stiff wind, “certainly could have sparked this blaze.”

Bartlett said police also were suspicious of Otterstrom’s behavior when they responded to his home. He said Otterstrom hid his fireworks in the bushes, turned his lights off and went to bed. Charging documents said he did not call 911 as the blaze broke out. 

Bartlett admits Otterstrom’s residence was not in the fireworks-restricted area. “But they didn’t charge him for being in a restricted area,” Bartlett said. “They charged him for reckless burning.”

Gill said police at first also failed to include a Unified Fire Authority report that included some “contradictory evidence” — which again cast doubt that Otterstrom was the culprit.

“When we started to look at all this contradictory evidence, which is our job … we realized [the case] couldn’t go forward, and we dismissed it,” Gill said. 

Following the fire, police reported they found several spent fireworks in the gutter in front of Otterstrom’s home, as well as unused fireworks hidden behind a garden planter, according to the charges filed against Otterstrom. He later admitted to police he set off aerial fireworks at his home but stopped when he realized a field near his home was on fire.

The blaze caused more than $1,500 in damage to the field behind Mountain View Memorial Cemetery, as well as fences, a play area, a shed and the home near  Banbury Road, charging documents said. 

Gill said his office has sent a letter to the Cottonwood Heights police department, explaining why charges were dismissed and stating that prosecutors would be willing to review any new evidence that shows someone else is culpable for the blaze.

On Friday afternoon, Cottonwood Heights police sent out a tweet: “The Salt Lake District Attorneys Office just dismissed charges on the 4th of July fire that threatened an entire neighborhood. Ask them why?”