The percussion-grenade tactics Eugene police used Thursday to arrest a suspected gang member with a criminal past mirrored those employed a year ago when the same team of officers apprehended one of the man’s alleged cohorts.

Police Sgt. Scott McKee acknowledged Friday that the Sheldon Plaza parking lot off Coburg Road was “not an optimal place” for officers to have deployed a percussion grenade shortly after 4 p.m. Thursday.

But the device — which works to disorient a criminal suspect by producing a blinding flash of light and an ear-splitting sound — allowed police to swiftly take assault suspect Cory Charles Weise into custody without a fight.

“We were trying to eliminate his ability to formulate a plan for escape,” McKee said.

The main downside of using a percussion grenade in a busy, public place is that it can frighten unsuspecting passers-by caught off-guard by the explosion.

“It can cause alarm (when) bystanders are shocked by the sudden impact,” McKee said.

A witness to a similar incident that unfolded in November 2012 in the busy parking lot of Costco on Chad Drive told The Register-Guard at the time that she had heard a loud blast and saw armed officers, causing her to initially believe that a man had been shot by police.

As it turned out, members of the police department’s special investigations unit had used a percussion grenade outside Costco to arrest the man, 34-year-old Beau Heleman Flynn.

Police say Flynn, a convicted felon who faces federal weapons charges in the case, is the leader of the West Side Gangsters, a prison gang that he and others formed in the 1990s in a west Eugene neighborhood.

Weise, a 31-year-old Eugene resident, is believed to have joined Flynn’s gang while in prison, McKee said.

According to state prison spokeswoman Elizabeth Craig, Weise served 13 months behind bars in 2003 and 2004. He spent four more years in prison after being convicted in 2005 in Lane County of charges that included first-degree burglary, unlawful use of a vehicle and being a felon in possession of a firearm.

Police on Thursday arrested Weise in connection with a prison-style stabbing of a man outside the Good Times Cafe in downtown Eugene on Oct. 4, McKee said.

Weise allegedly used an “improvised stabbing devise, such as those used in prison” to carry out a “violent, rapid, unprovoked attack” that left the victim bleeding from 11 stab wounds, McKee said. Police allege that Weise was at the bar with other West Side Gangster members when the incident occurred.

After being arrested Thursday, Weise was lodged in the Lane County Jail on a second-degree assault charge, as well as on additional counts of drug possession and delivery of a controlled substance within 1,000 feet of a school. He is also being held on a federal charge of being a felon in possession of a firearm.