ROCHESTER HILLS, Mich. — An 8-year-old boy who was shot in the head in a mass shooting at a Michigan splash pad is making "amazing progress" in his recovery, the local sheriff said.

The 8-year-old, his 4-year-old brother and their mother were among nine people shot at the Brooklands Plaza splash pad in Rochester Hills on Saturday, according to officials.

The suspect, Michael William Nash, allegedly fired 36 shots before fleeing the scene and then dying by suicide at his home, authorities said.

The 8-year-old boy and his mother, 39, remain in critical condition, Oakland County Sheriff Mike Bouchard said at a news conference Monday.

The 4-year-old brother was shot in the thigh and is in stable condition, the sheriff said.

The sheriff said he met with the family, noting that out of their family of four, three are in the hospital.

"Reeling would be an understatement," Bouchard said. "That poor family went through things that no family should ever have to face."

The 4-year-old is among five victims in the hospital in stable condition, the sheriff said.

The two other victims have been released from the hospital, the sheriff said Monday.

All victims besides the two brothers are adults, officials said.

Nash, 42, apparently had two handguns with him at the scene, the sheriff said.

Authorities recovered a trove of other weapons from Nash's home, including handguns, rifles and shotguns, the sheriff said.

A motive in the mass shooting hasn't been determined, Bouchard said.

It appears Nash "had been musing about different things, saying, 'Shut your phone off, we’re being watched, they are listening to us.' Walking around the house with weapons ... talking about how the government was tracking him," Bouchard said.

"It appears to me ... he's had some mental health things going on," the sheriff said, adding there's no information these apparent mental health issues were brought to anyone’s attention.

The splash pad shooting came hours before another mass shooting at a Juneteenth celebration in Round Rock, Texas, that left two dead and 14 injured.

The White House is coordinating with officials in Michigan and Texas, White House press secretary Karine Jean-Pierre said Monday.

"The president has been tracking these tragedies. We are praying for the families who lost loved ones to this senseless violence and wishing all those who were injured a speedy recovery," she said.

"As the president has said, this is not normal, and Congress must act. At the same time, he will continue to use every tool at his disposal to end the epidemic of gun violence that is tearing our communities apart," she said.

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