Forensics, Defendant's Interview Highlight Hamilton Trial Day 3

By Dani McCulley

Jurors in the first-degree murder trial of Jacob Hamilton heard testimony Monday, May 18, 2026 from a  firearms examiner with the Iowa Division of Criminal Investigation and the state medical  examiner as attorneys continued examining physical evidence connected to the July 2024  shooting death of Zachary Drinovsky in Hudson. 

Kristin Hart, supervisor of firearms for the Iowa Division of Criminal Investigation, testified for  the state regarding forensic testing conducted on the Walther PPQ 9 mm handgun recovered at  the scene. 

Hart explained that firearm examiners analyze markings left on cartridge casings and bullet  fragments to determine whether they were fired from a specific weapon. She testified that she  test-fired the Walther handgun recovered in the case and examined cartridge casings and bullet  fragments recovered during the investigation. 

According to Hart, the firearm functioned properly during testing and showed no mechanical  issues. She also demonstrated for jurors how the semi-automatic handgun operates, explaining  recoil, cartridge ejection and chambering during the firing process. Hart testified the firearm was  capable of holding 15 rounds in the magazine and one round in the chamber. 

Hart told jurors she compared test-fired casings and bullets to evidence recovered from the scene  and fragments recovered during autopsy. She testified the evidence was consistent with having  been fired from the Walther handgun recovered during the investigation. 

During cross-examination, defense attorney Konrad Kamizelich questioned Hart about  limitations in firearm scene reconstruction and casing analysis. 

Kamizelich asked Hart whether DCI conducted Griess testing, which can be used to help  determine muzzle-to-target distance. Hart testified the testing was not conducted and explained  that while the testing exists, DCI does not perform it at their office due to personnel limitations. 

Hart also acknowledged that numerous variables can affect where shell casings land after being  ejected from a firearm, including grip, movement, shooting position and whether the weapon is  fired with one or two hands. 

“There is no universal answer” regarding casing patterns, Hart testified when discussing the  various factors that can influence shell casing locations. 

Jurors also heard testimony Monday from forensic pathologist Dr. Jonathan Thompson, a  physician and medical examiner involved in the investigation. 

According to testimony, Drinovsky sustained multiple gunshot wounds during the incident,  including wounds to his arm, abdomen, leg and back. Thompson testified several of the injuries  involved both entrance and exit wounds. One gunshot wound shattered Drinovsky’s femur,  which Thompson said would have left him incapacitated.

Testimony also addressed Drinovsky’s blood alcohol concentration, which Thompson said  measured .134 several hours after the shooting. 

Thompson further testified there was no way to determine the order in which the gunshot wounds  occurred or the sequence in which the bullets struck Drinovsky.

Following the medical examiner's testimony, the state called Mark Herbst, who served as Captain & Chief Deputy with the Black Hawk County Sheriff’s Office at the  time of the incident. Herbst testified he had worked for the sheriff’s office for approximately 32 years and was asked by Hudson Police Chief Daniel Banks to oversee the investigation. 

Herbst testified he arrived at the scene around 5:10 a.m. after the area had already been secured. He told jurors  his role primarily involved conducting interviews as part of the investigation. 

According to Herbst, he later interviewed Hamilton at approximately 8:30 a.m. at the Black Hawk County  Sheriff’s Office after Hamilton was advised of his Miranda rights and signed a waiver form. Portions of the  recorded interview were played for jurors throughout the afternoon. 

During the interview shown in court, Hamilton told investigators there had been an altercation earlier in the  evening at The Hive bar involving Abbie Oglesbee and Emily Drinovsky, but stated Zachary Drinovsky was not  present during that incident. 

Hamilton told Herbst he returned home after leaving the bar and later fell asleep on his couch while caring for  his dog, Gigi, which he described as being in poor condition. 

In the recorded interview, Hamilton stated he awoke to Drinovsky inside his apartment. 

“He kicked the door, or broke in my house, or however he got in,” Hamilton said during the interview played  for jurors, later adding, “I usually lock my door.” 

Hamilton told investigators Drinovsky grabbed him and accused him of putting his hands on his wife, Emily  Drinovsky. Hamilton responded that he told Drinovsky to calm down and said, “We can talk about this  tomorrow.” 

Hamilton stated he believed the confrontation had ended and returned inside his apartment before realizing the  dog had gotten outside. 

Jurors also viewed portions of the interview in which Hamilton described going back outside near the apartment  entrance and dog ramp area. Hamilton repeatedly stated, “I don’t think I was that far out,” while describing his  location during the shooting. 

Herbst testified Hamilton gave varying descriptions regarding Drinovsky’s movements near the vehicle and  apartment area. He also stated he was in contact with investigators at the scene throughout portions of the  interview. 

According to testimony, investigators questioned Hamilton about shell casings recovered near a garbage can,  which Herbst stated did not appear consistent with where Hamilton placed himself during the shooting. Herbst  repeatedly pressed Hamilton about the casing locations throughout the interview. 

Jurors viewed video of Hamilton drawing a sketch of the exterior apartment area, including grills, vegetation, a  turf area and a ramp built for the dog near the doorway. 

Herbst testified Hamilton consistently placed himself near the dog ramp with one hand pushing the dog inside  while holding the firearm in the other hand.

During the interview, Hamilton stated he believed Drinovsky may have had a gun, but acknowledged he never  actually saw one. 

“As much as I act like I’m tough, I was scared,” Hamilton stated during the recorded interview. 

Hamilton later added in the interview that Drinovsky allegedly threatened to kill him while inside the apartment  and later continued yelling threats outside. Hamilton then stated Drinovsky said he “had something” in his  vehicle. 

The interview included discussion regarding the firearm used during the shooting. Hamilton described the  handgun as fully loaded and explained how shell casings eject “to the right and back” when fired. 

Hamilton stated he believed he fired the gun two or three times and demonstrated multiple shooting scenarios  during the interview, including one in which he appeared to look toward Drinovsky while standing and another  in which he demonstrated looking away while crouched down and pushing the dog toward the apartment. 

Hamilton also told investigators he could not clearly see during the incident and stated he stopped firing once  Drinovsky fell near the driver’s side door of the vehicle. 

According to the interview played for jurors, Hamilton told investigators he checked Drinovsky for a weapon  after the shooting but did not find one. Hamilton then heard Abbie Oglesbee speaking through a Bluetooth  connection from Drinovsky’s vehicle, grabbed the phone from the center console and told Oglesbee to call 911,  saying, "He broke into my house and I shot him."

Hamilton also stated he applied pressure to Drinovsky’s wounds with a towel until emergency responders  arrived. 

Testimony concluded for the day. Herbst was scheduled to continue testimony Tuesday morning.