"We know we have witnesses...We just need people to feel comfortable to bring it forward," said a police chief.
Although he is 15-years-old, he is charged and will be tried as an adult. Due to the plea, his case will now go to the Oakland County Circuit Court.
Officers said drugs and assault rifles were involved and criticized witnesses who "don't want to be seen as snitches."
Videos posted to social media show people rushing to get out of the mall after the shots rang out.
Eve Primus, a professor of criminal law at University of Michigan's Law School, said the decision to try Ethan as an adult could have implications on the Crumbley manslaughter charges.
Police in Florida said they arrested a 19-year-old for allegedly "plotting to shoot up the campus on the final day at the school before winter break."
"As a female and a Realtor, thank you for allowing my right to bear arms," Jennifer Crumbley allegedly wrote in a blog post addressed to Donald Trump.
He told the couple to lock up as he left in the evening, his lawyer says. Police escorted them out at about 2 a.m.
They would often leave their son home alone while they went to bars, and "he would come knock on our door," she said.
"I want universal background checks...but I will settle for something much less because that will save lives," Senator Chris Murphy said.
A Michigan teen faces a 20-year felony charge after admitting to posting a threat that included a firearm image, police said on Friday.
"Making a false threat of terrorism is a felony and could result in 20 years imprisonment," police reminded parents and students on Friday.
"No discipline was warranted. There are no discipline records at the high school," said Oakland Community Schools' superintendent Tim Throne.
Clayton County field training officer Henry Laxson was killed responding to a domestic violence call.
The attacker's friends and peers did not know about his violent fantasies, leading the report to conclude "bystander fatigue" contributed to the shooting.
A month after Nikolas Cruz pleaded guilty to 17 counts of murder, attorneys for the families of those killed announced a settlement has been reached.
In footage released Saturday he appears to set fire to a banner on the memorial's wall using a lighter, and as the blaze grows, he leaves the premises.
The group behind the event offers boxing lessons as an alternative way of venting anger and frustration.
Eight people were shot, and one died from his injuries, police reported Saturday.
Doctors said Ahmad Al Aliwi Alissa had a "passive approach to his defense" and was potentially overreliant on his attorneys. Prosecutors are seeking another evaluation.
Multiple shooters are suspected in an incident described by St. Paul officials as "nothing short of a tragedy."
The 4th U.S. Circuit Court of Appeals denied Roof's request for a new appellate hearing, so his original conviction and sentence still stand.
The judge said Ramos showed no remorse for the crimes and reportedly told a state psychiatrist that he would kill more if released.
"He kept on shooting, shooting, shooting. He shot one of my co-workers in the head and shot one of my customers in the stomach," an employee said.
Oleg Syromyatnikov carried on teaching when a gunman went on a rampage at Russia's Perm State National Research University.
Joseph eventually advanced from spreading violent messages online to planning a real-life violent attack on Jewish community members near his home.
The suspect, who police said described himself as a survivalist, is being treated at a hospital for injuries sustained during a gunfight with officers.
The president made the claim during Thursday remarks to Jewish leaders ahead of the Rosh Hashanah holiday.
The move comes after a mass shooting in Plymouth, England where a man killed himself and five others, including his mother and a 3-year-old girl.
The mass shooting in Plymouth is the U.K.'s first since 2010.