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SAN TAN VALLEY — A partial investigation report obtained from the Maricopa County Sheriff’s Office states that Cooper Lamb, son of Pinal County Sheriff Mark Lamb, may have been impaired by drugs or alcohol when he struck and injured a bicyclist with his car in July.

A toxicology report is still pending and no charges have been filed against Cooper Lamb, 20, at this time.

The crash happened around 6:45 p.m. on July 8 on Gary Road near Judd Road in San Tan Valley. Pinal County deputies were originally called to the scene, but the Maricopa County Sheriff’s Office Vehicle Crimes Unit was asked to take over the investigation by Sheriff Lamb after it was determined that the driver of the car was his son.

After completing a drug influence evaluation of Cooper Lamb at a Pinal County substation, an MCSO deputy from the Vehicle Crimes Unit stated in his report, “It is my opinion, as a certified drug recognition expert, that Cooper was impaired by a central nervous system depressant and cannabis and was unable to operate a motor vehicle safely.”

The evaluation included drawing four tubes of Lamb’s blood to test for various substances. The blood was sent to the Arizona Department of Public Safety’s crime lab. MCSO is still awaiting the results of those tests.

The full investigation report of the incident has not been released because the investigation is ongoing.

According to the MCSO report obtained by PinalCentral through a Freedom of Information request, Maricopa deputies arrived on the scene of the accident around 7 p.m. The report states that the victim was found on the shoulder of the road and had been flown to Chandler Regional Medical Center by helicopter with life-threatening injuries.

The report also notes that the road conditions were dry, level, with no apparent distractions or hazards. It estimates the speed of Lamb’s car at 50 to 52 mph in a 35 mph zone. It states that Lamb’s vehicle ran off the right side of the road and struck the bicyclist.

A deputy from MCSO’s Vehicle Crimes Unit arrived to investigate the scene and talk to Lamb around 9:15 p.m. According to the deputy’s report, Lamb told him that he did not have his license with him but was driving north on Gary Road from his home to get food. Lamb said as he was approaching Judd Road he heard a thump. Realizing he had hit something, he stopped, exited his car and started searching for what he had hit. He found the bike in the roadway and then found the bicyclist nearby.

“Cooper said he was unsure but he believed that the bicyclist had pulled in front of him,” the deputy stated in his report.

The deputy, who is a trained drug recognition expert, then gave Lamb several field sobriety tests. He noted that Lamb was calm and cooperative but had thick, slurred speech, watery eyes and would occasionally sway from side to side approximately 1 to 3 inches. Lamb was dressed in pajamas and socks.

“There was an uncommon delay in some of his responses to me as if he was having trouble comprehending some of the questions I had asked him,” the deputy stated in the report.

According to the report, Lamb had trouble completing some of the sobriety tests. It states that Lamb was unable to “stand in the instructional position, stepping out of position several times and then standing normally for the remainder of the instruction.”

It also describes Lamb as having “wobbly” legs and says that during one test Lamb said he would stand on his left foot and raise his right foot, but did the opposite. He also had trouble counting and following directions. He was placed under arrest at the scene for driving while impaired and taken to a PCSO substation for a further evaluation and to draw blood.

The MCSO deputy asked Lamb at the scene and at the substation if he was taking any medication. According to the report, Cooper Lamb first told the deputy at the accident scene that he had been taking an antidepressant, mirtazapine, but stopped taking the medication a month before. Lamb later told the deputy at the substation that he had stopped taking the medication about two weeks before. When asked about the discrepancy, Cooper stated that he had been prescribed the medication at the beginning of June and taken it for most of the month but had stopped taking it at the end June.

The side effects of mirtazapine include dizziness and drowsiness, according to WebMD. The website recommends avoiding alcohol and marijuana while taking mirtazapine and to avoid driving or operating heavy machinery until a person becomes used to the effects of the medication.

According to the report, Lamb also told the MCSO deputy that previously he had a medical marijuana card and did smoke marijuana and use edibles, but stopped after the card expired in April.

During the interview at the substation, Lamb told the deputy that he had nothing to eat all day and had only had one cup of water. He also told the deputy that he had last slept for about three or four hours around 10 a.m.

Lamb’s vehicle was impounded as part of the investigation. The impound record for the Chevrolet Sonic, a four-door sedan, lists damage to the vehicle’s hood, grill, windshield, driving lights and engine.


Suzanne Adams-Ockrassa is a reporter covering the city of Casa Grande and the surrounding area, as well as Central Arizona College. She can be reached at sadams@pinalcentral.com.