Police went to Robinson's Sugar House home on Tuesday after a burglary was reported there, said Sgt. Robin Heiden.
Heiden would not disclose who reported the break-in. During that investigation, officers found enough evidence for a search warrant and discovered a "small amount" of cocaine and a "large quantity" of marijuana along with scales and "numerous" marijuana pipes and water bongs, according to jail documents. They also found large sums of cash and four guns; possession of a firearm is illegal if the owner also is in possession of illegal drugs, Heiden said.
Robinson was booked into the jail on suspicion of possession of marijuana with intent to distribute, cocaine possession, possession of drug paraphernalia and illegal weapons possession. His sons were booked on suspicion of drug possession and possession of drug paraphernalia.
Salt Lake County Attorney Sim Gill said his office has been involved in the investigation and expects to receive the case from police Thursday afternoon.
Heiden said the charges may be enhanced because the home is within 1,000 feet of Clayton Elementary School.
Although Robinson works alongside the police department, he does not have regular contact with rank and file officers, nor is he involved with criminal cases, Heiden said; if he were an officer or prosecutor, the case would have been transferred to another agency.
"He's a city employee," Heiden said. "If it happens in our jurisdiction, we investigate it, just like a garbage truck driver or any other employee."
Gill agreed there appears to be no conflict of interest.
"It's a fairly straightforward set of facts," Gill said. "They've done a very thorough, careful job with that [investigative] process."
Robinson has worked for the city attorney's office since 2000. According to an online profile, he previously worked at the state attorney general's office.
Robinson and one of his sons bailed out of jail late Thursday afternoon; each were held on bail of just under $12,000. His other son bailed out Wednesday night.