Defense challenges reconstruction testimony as jurors view recovered firearm, Ring footage during fifth day of Hamilton murder trial

By Dani McCulley

Competing forensic interpretations took center stage during the fifth day of the Hamilton murder trial on Wednesday, May 20, 2026.

Jurors in the first-degree murder trial of Jacob Leigh Hamilton heard continued testimony Wednesday from Iowa State Patrol Trooper Eric Payne, with much of the day focused on competing interpretations of shell casing evidence, bullet trajectory analysis and the limitations of forensic scene reconstruction connected to the July 2024 shooting death of Zachary Drinovsky in Hudson.

The testimony continued from Tuesday, when Payne introduced digital scene mapping exhibits created from laser scan data, shell casing locations and bullet trajectory paths.

Assistant Iowa Attorney General Israel Kodiaga continued presenting demonstrative exhibits showing projected shell casing ejection patterns and trajectory cones extending backward from bullet defects identified in Drinovsky’s SUV.

Payne testified the diagrams were created using scene measurements, shell casing locations documented by investigators and test-fire data generated from Hamilton’s firearm.

One demonstrative shown during testimony included a digital avatar dog positioned near the apartment doorway. Defense attorney Nicole Watt objected after the image was displayed to jurors before the defense had an opportunity to challenge the exhibit outside the jury’s presence.

Watt moved for a mistrial, arguing the demonstrative was improperly shown to jurors before objections could be addressed. She also noted there had been no testimony establishing the dog’s exact size or location at the time of the shooting.

Judge Joel Dalrymple denied the mistrial request but instructed jurors the image was only a hypothetical demonstrative and not intended to represent the actual dog involved in the incident.

Payne later testified the avatar was used only as a visual reference based on information that Hamilton’s dog was near the doorway during the shooting.

Kodiaga then questioned Payne about projected shell casing “ejection radius” circles generated from test-fire data. Payne testified the circles were intended to show generalized regions where shell casings would be expected to land if fired from certain positions.

Using those projections, Payne testified the casing locations documented at the scene were not consistent with shots being fired from the doorway area described in Hamilton’s account. Payne testified the shell casings were recovered more than 20 feet from the apartment doorway and that test-fire ejection patterns from Hamilton’s firearm generally projected casings shorter distances.

Payne also testified the trajectory rods and cones shown to jurors were intended only to show the possible path of travel immediately before bullets struck Drinovsky’s SUV, not Hamilton’s exact position.

During cross-examination, Watt focused heavily on the limitations of Payne’s analysis and the assumptions used in the modeling.

Payne testified he did not begin reviewing the case until a few months ago and that his analysis relied on measurements, photographs and scene data given by the Black Hawk County Sheriff’s Office and Hudson Police Department.

Watt repeatedly questioned Payne about the limited number of test-fired shell casings used to create averages shown in the demonstratives. Payne acknowledged investigators only had a small number of matching shell casings available from Hamilton’s firearm and agreed larger sample sizes generally produce more reliable averages.

Watt emphasized that portions of the testing relied on averages generated from only two shell casings.

She also highlighted differences between the testing environment and the apartment complex scene, noting the shell casings during testing landed in sand while the casings recovered after the shooting were found on a harder surface.

To illustrate her point, Watt repeatedly dropped shell casings onto the courtroom floor in front of jurors, demonstrating how the casings bounced differently and came to rest in different locations despite being dropped from nearly the same position.

Payne agreed shell casings can behave differently depending on the surface they strike and acknowledged factors such as movement, slopes, surface texture and environmental conditions can affect where casings ultimately come to rest.

However, Payne maintained the casings still remained within a generally consistent region.

Watt also questioned Payne about whether he had reviewed a hand-drawn diagram Hamilton reportedly made during his police interview identifying multiple possible locations where he may have been standing during the shooting.

Payne testified he had not seen the diagram and was unaware Hamilton had reportedly identified more than one possible position.

Throughout the testimony, Payne repeatedly clarified he was not attempting to identify Hamilton’s exact location when the shots were fired.

“I’ve never at any point been able to say where the weapon was fired,” Payne testified, explaining his role was to compare physical evidence and spatial relationships documented at the scene.

Payne testified his analysis was intended to show possible regions where the evidence aligned, not to pinpoint an exact location. However, he testified the physical evidence appeared more consistent with shots being fired farther down the driveway and closer to Drinovsky’s SUV than from directly near the apartment doorway.

Following Payne's forensic scene mapping, Black Hawk County Sheriff’s Office investigator BJ Heath was recalled to the stand by the prosecution.

Jurors were shown photographs of Hamilton taken on July 16, 2024, which were introduced after investigators testified that Hamilton reported having no injuries following the shooting.

Before testimony regarding a firearm recovered from Drinovsky’s vehicle, Dalrymple read a limiting instruction to jurors explaining the firearm could only be considered for specific purposes, including where it was found, how it was recovered and whether evidence showed it had been used, displayed or handled near the time of the shooting.

Dalrymple instructed jurors they could not assume Drinovsky had the firearm in his hand, pointed it, threatened anyone with it or reached for it when Hamilton fired.

Jurors were then shown photographs of the firearm recovered from the SUV. Heath testified the Ruger SR9 9mm handgun was found holstered inside the passenger-side compartment area of the vehicle and was not readily accessible from Drinovsky’s position.

Heath also testified investigators found no shell casings associated with the firearm and no evidence indicating it had been fired during the incident.

Additional testimony addressed bullets recovered from inside Drinovsky’s SUV. Heath testified investigators located bullets beneath the driver-side center console area, beneath carpeting on the driver’s side and inside the dashboard.

Jurors also heard testimony that two of the seven shell casings believed to have been fired during the incident were never recovered.

The prosecution additionally introduced a 31-second Ring camera video showing Drinovsky outside his residence around 3:13 a.m. shortly before the shooting. Heath testified the footage showed Drinovsky outside while speaking on the phone.

During cross-examination, defense attorney Konrad Kamizelich questioned Heath about how investigators obtained the footage and whether additional video may have existed.

Heath testified the footage was received by email from Emily Drinovsky on Aug. 27, 2024. Kamizelich questioned whether investigators knew if the clip represented the complete recording from that night.

Heath testified investigators requested any available footage but did not receive any. He also acknowledged he did not obtain a search warrant to retrieve additional video directly from Ring.

Kamizelich also questioned Heath about whether additional footage before or after the submitted clip could have existed.

Following Heath's cross-examination, the state called Kenneth Martin as an expert witness in bloodstain pattern analysis.

Martin stated he first reviewed the case March 10, 2026, examining photographs, body camera footage, autopsy findings, police reports, forensic mapping data and interview transcripts in forming his opinions.

Martin noted that in bloodstain analysis, “the absence of blood is just as important as the presence of blood.”

He explained his analysis considered blood patterns, body positioning, movement, surface conditions and possible actions of both the victim and suspect. Martin added he visited the physical scene after reviewing photographs and digital scans in order to evaluate the layout, ground surfaces and overall environment.

Martin also reviewed forensic mapping data generated from the Faro scan, reports from multiple agencies, autopsy findings, shell casing testing and video interview transcripts from Hamilton.

Martin’s testimony was scheduled to continue Thursday morning in Black Hawk County District Court.