RICHMOND (CBS SF) — An unusually violent 48 hours in the city of Richmond has police calling in the FBI and patrolling vulnerable neighborhoods to discourage retaliatory shootings this week, according to a message from Chief Allwyn Brown.

Investigators believe there may be a link between two shootings in Richmond on Monday and one of several that occurred on the previous day, Brown said in a letter to city officials that was shared with the public Wednesday morning by Mayor Tom Butt.

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Around 4:15 p.m. Monday, officers responded to a ShotSpotter activation in the 500 block of Duboce Avenue in which at least one person was injured, but none of the parties believed to be involved cooperated with the police investigation.

About an hour later another gunshot victim was found in the vicinity of South Sixth Street and Ohio Avenue. He was also uncooperative, but investigators found the alleged crime scene at Sixth Street and the Richmond Greenway.

Sunday, three separate shootings were reported between 10:10 p.m. and 11:25 p.m. The first shooting appears to have occurred in the 2400 block of Esmond Avenue in connection with the robbery of a man and a woman in a minivan. The woman was shot while fleeing, and the man was shot several times where he was sitting in the vehicle.

Police say his injuries left him paralyzed.

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Then around 10:35 p.m., another man was shot in the vicinity of Nevin Avenue and First Street. The 29-year-old victim walked into an emergency room and later told investigators that he had been walking in the area when a dark-colored sedan rolled up and he saw a laser. He ran but was shot in the foot.

Then around 11:25 p.m., a citizen of Eritrea was shot as he was standing near an apartment building on Potrero Avenue. Police said that he was ambushed by two armed suspects who opened fire and fled to a waiting vehicle.

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The victim, identified as 44-year-old Embaye Maekele Amariam, was transported to a hospital in grave condition and has since been declared brain dead. Brown said he’s not likely to survive.

“While his shooting was obviously targeted, it is possible that he could have been mistaken for someone else (he was wearing a hood) or a target of opportunity meant to send a message to rivals,” Brown said. “We are considering the possibility that this shooting could have sparked subsequent attacks that happened on Monday.”

In a sixth and potentially unrelated shooting, 56-year-old Miguel Ramirez was killed outside his home Tuesday evening. Officers responded to the 1600 block of Chanslor Avenue and found him wounded. He was pronounced dead at the scene.

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Richmond police spokesman Lt. Matt Stonebraker said Wednesday morning there were no details about the suspect or motive that could be released to the public at that time.

The city of Richmond made great strides to reduce gun violence in recent years, and the sudden spike in shootings seen since Sunday night has prompted the police to seek assistance from the FBI Safe Streets Task Force.

Officers are keeping a visible presence in areas they fear may be subject to retaliatory violence while gang experts pursue other forms of intervention, Brown said.

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