Kevin Matthews was shot to death during a struggle with an officer who had chased him along the Dearborn-Detroit border around 12:30 p.m. Wednesday, Dec. 23, 2015, according to Dearborn police.

DETROIT -- A key piece of dashcam video footage related to a fatal 2015 police shooting of a mentally ill man was damaged before it could be reviewed, and the cause of the damage was not revealed for more than a year and a half.

The cause of the malfunction was never relayed by police to the Wayne County Prosecutor's Office, which cleared the officer of wrongdoing in 2016.

The video in question, from the dashboard-mounted camera of Dearborn Police Cpl. Chris Hampton, who shot and killed Kevin Matthews on Dec. 23, 2015, was "corrupted," Detroit police said in response to an MLive records request after the investigation concluded.

With help from the Secret Service, the prosecutor's office eventually recovered about 13 seconds of video footage. It included no audio and did not show the shooting, only the beginning of the foot chase that preceded it.

The recovered footage was of little help to investigators, and prosecutors in December 2016 announced that the probe didn't yield enough evidence to warrant criminal charges against the officer, and that Matthews in self defense.

In the months that followed, numerous efforts by MLive to obtain records related to the case yielded incomplete results that illustrate the difficulty of reviewing and making public video footage and police documents from officer-involved shootings in Metro Detroit.

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The shooting

Dearborn Police Officer Chris Hampton was conducting an unrelated traffic stop when he spotted Matthews, who was wanted for stealing a Red Bull from a Dearborn gas station the night prior, walking nearby at 12:27 p.m. on Dec. 23, 2015.

Hampton abandoned the traffic stop and drove after Matthews, ordering him to stop. Matthews ran away and Hampton exited his police car. The chase ended with a struggle in the backyard of a home and Matthews was shot nine times.

Within minutes, more than a dozen Dearborn police vehicles swarmed the scene.

In a phone call made to police headquarters from the scene at 2:11 p.m., according to the time stamp on an audio recording obtained by MLive, an officer asked to have the police garage cleared so she and another officer could bring in two police vehicles, including Hampton's, that "possibly" contained dashcam footage from the incident.

"O.J. wants them pulled into the sally port so they can be downloaded immediately," the officer said.

Most modern dashcam systems automatically upload police footage to a network server using WiFi, which eliminates the need for manual transfer. It's unclear whether Dearborn had this capability - and if so, why investigators chose to upload the video manually -- because police refuse to discuss their system.

L3 Technologies, Dearborn's dashboard camera provider, advertises its products as being equipped with "hands-free evidence upload" capability.

The 2:11 p.m. phone call contradicts notes in an Aug. 16, 2016, seven-page internal memo from Dearborn Police Lt. Ronald Beggs of the Investigative Division to Chief Ronald Haddad about the corrupted dashcam video.

Internal memo:

That report says a Cpl. Urbanick was ordered at 12:40 p.m. to instead manually remove the video storage disk from Hampton's car, which he died about 12:58 p.m., nearly a half-hour after Matthews was killed. There is no mention in the memo of attempts to upload the video through wireless means.

The report says Ubanick followed "standard procedures" for removing the storage disk, but video and audio from the interaction with Matthews were never uploaded to a computer.

"While reviewing videos Dec. 23, 2015, the IT Unit observed that Cpl. Hampton's vehicle has successfully recorded and uploaded three videos; however, there was no footage captured after 12:27 p.m. on Dec. 23, 2015," the report says.

Dearborn did provide clear video with sound from the traffic stop Hampton conducted minutes before the Matthews pursuit. The city also released to MLive video from a second vehicle to arrive at the scene, but that video, without explanation, was void of sound.

While a Dearborn police representative told MLive that officers do where body microphones, no audio from the Matthews shooting was released.

Representatives of L3 Technologies, the New York-based company that provides Dearborn its dashcam systems, offered remote support to police a day after the shooting, but could not access the video.

The storage disk was turned over to Detroit police detectives, who were conducting an independent, third-party investigation into the shooting, on Dec. 28, 2015.

'There will be questions'

In June 2016, Detroit police questioned an official at L3 about the cause of the malfunction, according to emails obtained by MLive. The official did not cite a specific cause, but noted several possible causes including possible tampering, battery or electrical systems failures.

There was no mention in the emails between L3 and Detroit police that Dearborn's IT Unit detected "widespread issues" with daschcam systems throughout the fleet in late January 2016, and arranged for the dashcam manufacturer and installer to review the systems in March.

An L3 technician, according to documents obtained from Dearborn via FOIA request a year and eight months after the shooting, determined the installer, Cynergy, had wired all of the dashcam systems improperly.

MLive made several phone calls to Cynergy attempting to verify the improper wiring claims, but representatives declined comment.

After noting the wiring issues, the internal memo says all of the dashcam systems in the Dearborn Police Department's fleet were rewired. According to communications obtained by MLive, the wiring problem was never shared with the Wayne County Prosecutor's office, nor with Detroit police.

"No, it was not revealed to us by Dearborn P.D.," assistant prosecutor and spokeswoman Maria Miller told MLive. "It was quite a while into the investigation that we learned of the wiring problem in the course of working with Internet Task Force personnel (first Secret Service, then West Bloomfield)."

The prosecutor's office was never made aware of the alleged the flee-wide wiring issues.

Detroit police independently sought their own answers from L3 regarding the cause of the missing video.

"I'm not asking you to lie or do anything unethical, but there will be questions to why the card malfunctioned and your company is the most qualified to give an explanation," Detroit Police Sgt. Derrick Maye wrote an email to L3 Technologies technical support engineer Spencer Stowers on June 29, 2016.

"If you want to send a list of possible explanations for the malfunctions outside the official letter, that would be greatly appreciated."

The message was in response to Stowers expressing concern that listing a cause would be "unethical," because there was, "no proof to back up any speculation that we might even have."

He asked Maye to call him to further discuss the possible causes of the video failure, but Maye said the prosecutor asked that the cause be put in writing.

Detroit police, in response to a Freedom of Information Act Request, provided communications between Dearborn police and the dashcam company, but initially denied knowledge of the emails between its own investigators and the company.

"I assure you we are not hiding or withholding any data," said former Detroit Police Media Relations Director Michael Woody. He later forwarded the emails, which were not included in the initial records release. Woody has since left the department.

Stowers told Detroit police in a June 30, 2016 email that "many different factors" could have caused the video to become corrupted, including: the video recorder could have malfunctioned due to a battery issue or it was "out of its hardware life"; the memory disk could be bad; or the police cruiser's battery or electrical system could have failed.

There are "endless possibilities," Stowers said. He never mentioned that an L3 representative spent three days in Dearborn correcting a widespread wiring issue, as noted in the Dearborn police memo.

Stowers' response included the possibility that the video was intentionally manipulated or erased.

A spokesperson for L3 Technologies, which has police department customers across the nation, wouldn't discuss the corrupted video with MLive and referred comment back to Dearborn police.

Eric Barnum, a video surveillance specialist who owns Spy-Ops in Lathrup Village, said most police dashcam systems use a hard drive recording system, and the video footage can be transferred to a portable memory disk.

Kenneth Glaza, an independent digital media forensics analyst, who works with Barnum, said there are a number of ways dashcam video files can become corrupted.

"There are a number of pieces as to why it could happen, and sometime its intentional, and other times it's stupidity, and the least likely reason is it just didn't work," he said.

'Terribly inexplicable'

"It seems to me that, when you've got a shooting case, that the video is the highest priority," said Romulus-based criminal defense attorney William Maze, who also specializes in Freedom of Information Act law. "This isn't like a routine traffic stop. Without explanation as to why it was corrupted, I'd have a lot of questions.

"First, you need to identify how it was corrupted and if it was corrupted by the transfer process or the in-car video system was malfunctioning."

Maze called it "terribly inexplicable" that the officer's prior traffic stop was recorded with sound and released, while everything after involving Matthews was lost.

Worthy's office took nearly a year to issue a ruling in the case, but found that Hampton killed Matthews in self defense.

Worthy's statement explaining the decision said it took nearly four months and technical assistance from the Secret Service to obtain and review the short dashcam clip.

A "technical difficulty with the system" was the reason given.

Jeffrey Ross, a spokesman with the Secret Service, said agents trained in technical forensics extracted portions of the dashcam video, but he was "not able to comment" on why only the short clip survived.

Audio

While audio and video footage from Hampton's car beyond the traffic stop was lost, numerous recordings of phone calls and dispatch communications were provided.

Hampton is heard telling dispatch in a calm tone about 12:27 p.m. he was "approaching one on foot" near Tireman and Whitcomb avenues.

About 30 seconds later, an urgent and inaudible radio call from Hampton. Seven seconds later, another, which sounds like Hampton was notifying dispatch he was "pursuing black male."

Another 30 seconds pass. "Tac-1. Code green," Hampton says, seemingly out of breath, but calmer. Another police unit was dispatched.

Another minute passed, and Hampton radioed to dispatch again:

"Tac-1, priority, shots fired," the officer said, breathing heavily

"Suspect down. I'm OK," he said. "The suspect has multiple gunshot wounds."

Medics were dispatched, but Matthews died on scene.

The moments after the shooting

Dearborn Police Cpl. Guerino Cerroni, the first officer on scene after the shooting, observed "visual bruising and cuts" on Hampton's hands, according to a report submitted to prosecutors by Detroit Police Detective Richard Houser.

Hampton also said Matthews "sprayed him with pepper spray (taken from Hampton's tool belt) and attempted to take his weapon," according to Houser's report.

Some of those details were left out of the prosecutor's summary of events.

Worthy's otherwise-thorough report clearing the officer never mentioned Hampton's injury, nor the pepper-spray attack.

Regarding the pepper spray, Miller said the prosecutor's investigation revealed the "Dearborn officer in question faced the possibility of being sprayed with the pepper spray, but was not actually sprayed."

Worthy said of the struggle:

A Dearborn police officer responding to the scene observed that the officer was kneeling in the middle of the driveway, close to the garage, next to Mr. Matthews, closer to his feet. "He found Mr. Matthews lying on his left side, facing west, with the officer still holding his weapon. The responding officer observed that the officer's uniform was disheveled, shirt untucked, with mud all over and a mark on his forehead. The officer was hyperventilating and staggering on his knees, so he grabbed him by his arm to help him up. The responding Dearborn officer said that the officer told him Mr. Matthews grabbed at his pepper spray and that Mr. Matthews attempted to take his gun. The responding officer took his weapon from him and gave it to another officer. He observed the Dearborn police officer's ammunition magazines on the ground. One was on the driveway under a barbecue grill, and one was on the driveway next to Mr. Matthews' feet. Items in the officer's duty belt were also spread around the scene.

The Detroit police detective's report lined up with Worthy's report regarding the ammunition being on the ground, but conflicted on the officer's gun, which Worthy's office said was taken from Hampton and given to another officer.

The Detroit police report says Hampton's gun, hat, pepper spray, handcuffs, pen and watch were all on the ground when investigators took scene photos.

In an audio recording of a phone call made to police headquarters from the scene at 12:45 p.m., according to the time stamp on the file, an officer is heard saying: "Did anyone grab the extra gun at position one?"

Another mentally ill person, Janet Wilson, was shot to death by a Dearborn police officer a month after the Matthews shooting.

The Dearborn police chief, despite claiming early on that he would maintain transparency throughout both investigations, denied multiple requests to discuss either incident.

After self-defense ruling, dashcam video released in police shooting of mentally ill woman.