The suspect who Oakland police say fired the gun that killed Oakland Police Officer Tuan Le on Friday morning has now been publicly identified, and it turns out he already served time for killing another man a decade ago, when he was still a juvenile.

Mark Demetrious Sanders, 27, was the "key suspect" whom Oakland police arrested overnight on Monday night/Tuesday morning in Livermore, the police now say. As the East Bay Times reports, Sanders was the third of three suspects arrested, with the other two — 30-year-old Sebron Russell and 28-year-old Allen Starr Brown — believed to have been accomplices in the December 29 burglary at an Oakland cannabis dispensary, outside of which the shooting took place.

None of the three have yet been charged, but Russell was booked on suspicion of second-degree burglary, and Brown was booked on Sunday on suspicion of murder, because police reportedly believe he was in the car and was possibly the getaway driver at the time of the shooting.

Sanders is being held at Santa Rita Jail on suspicion of murder as well.

Update: Both Sanders and Brown were charged with murder late Wednesday and will make their first court appearances Thursday.

The trio allegedly targeted the cannabis business on the 400 block of Embarcadero in Oakland, identified by KTVU earlier today as Peakz, twice in the early hours of Friday morning. The first burglary report came around 1 a.m. Friday, and police responded to the scene following a report by a good Samaritan who witnessed the burglary in progress.

Police cleared the scene, but it sounds like they made no arrests. And it seems the same crew returned about three and a half hours later to finish the job, at which point multiple police in the area responded again.

Le was on plainclothed detail with the burglary suppression unit, and he was fatally shot while in a responding vehicle with another plainclothed officer — an unmarked white Toyota Tacoma pickup truck.

Oakland police believe that Sanders opened fire on the police, even though police had not fired on the suspects, and it seems unclear whether they knew they were police.

Sanders was previously arrested and charged with the February 2014 homicide of 18-year-old Marcellus Perry. Per the East Bay Times, Perry was killed in a shootout near Bancroft and 77th avenues, and Sanders, then 17, ultimately pleaded no contest to voluntary manslaughter and was sentenced in juvenile court to 10 years — though he only ended up serving five. That would mean he was released from prison around 2019.

Sanders reportedly has had residences in Stockton, Vallejo, and Oakland.

Sanders and Russell, along with a third individual, also have a burglary conviction on their record from 2021 in Contra Costa County. Both are still on probation for that crime, having served six months starting in 2022.

Previously: Oakland Police Make 'Several' Arrests In Connection With Fatal Shooting of Officer Following Dispensary Burglary

Photo of Sanders via Alameda County Sheriff's Dept.