The 20-year-old Pennsylvania man who attempted to assassinate former President Donald Trump conducted internet searches into a recent high-profile shooting that brought landmark convictions against both of that shooter's parents for ignoring warning signs about their son, sources tell CBS News. 

Gunman Thomas Crooks's smartphone search focused on Michigan high school shooter Ethan Crumbley's parents, FBI and Secret Service officials told members of Congress Wednesday, according to two sources familiar with the briefing. The shooter's internet search history, which also included images of Trump and President Biden, did not bring investigators any closer to a motive, the sources said. 

That detail, that he may have been considering the impact of such an act on his parents, may provide a little insight into Crooks' frame of mind in the time leading up to his decision to open fire on Trump during a crowded rally in Pennsylvania. It also raises questions about whether his parents could face any legal consequences, since prosecutors are increasingly using novel legal theories to hold gun owners responsible for their children's actions.

But experts told CBS News there is still too little known about what Crooks' parents knew and did in the days and hours leading up to the shooting to make an assessment about potential legal fallout. 

"The facts would need to approach or exceed the egregious level of the Crumbley case: multiple serious warning signs over a longer period of time, improper storage, close involvement with the shooter's use of guns, etc.," Andrew Willinger, executive director of the Duke Center for Firearms Law, said.

James and Jennifer Crumbley were each sentenced to 10 to 15 years in prison earlier this year after juries in Michigan found them guilty of involuntary manslaughter. The rare case was considered historic, since the parents were held responsible for the crimes of their child, who killed four students and injured seven other people in the Oxford High School shooting on Nov. 30, 2021. 

And last November, the father of a 19-year-old accused of killing seven people at a 4th of July parade in Highland Park, Illinois, pleaded guilty to seven misdemeanor counts of reckless conduct. Prosecutors alleged the man should have known his son was a danger to the public when he signed his application for a Firearm Ownership Identification Card. 

The AR-style rifle used in Saturday's attack was owned by the gunman's father, Matthew Crooks. Law enforcement sources said the gun was legally purchased in 2013.

Matthew Crooks called police before the shooting at the rally, concerned about his son and his whereabouts, a law enforcement source told CBS News. The family is cooperating with federal investigators, according to the FBI. 

Adam Garber, executive director of CeaseFire PA, a gun violence prevention organization in Pennsylvania, said the details of that call to local police, or what the parents knew and when, could yield more answers as to whether charges may be brought. 

"The DA will need to ask two key questions. First, what did the parents know about their son's intentions and when did they know it?" Garber said. "Second, how did their son get the firearm — and did they know where he was taking it? Those questions of the intent and access are key to assessing their culpability."

According to both Willinger and Garber, based on what is known now, it is unlikely that Crooks' parents will be held criminally liable for their son's actions because Pennsylvania does not have a safe storage law, a requirement that generally applies to gun owners to secure firearms in homes with minors, and because he was over the age of 18.

"Ultimately, it will be up to the district attorney to determine if there is anything to charge," said Garber.

In:
• Pennsylvania
• Ethan Crumbley
• Trump Rally
• Donald Trump