Opening statements got underway Thursday in the trial of Jennifer Crumbley, the mother of the teen gunman who opened fire at Michigan's Oxford High School in 2021, killing four students. Crumbley and her husband are both charged with involuntary manslaughter, accused by prosecutors of purchasing for their son the gun used in the shooting, as well as ignoring warning signs of mental health issues. Elaine Quijano has more. "CBS Evening News with Norah O'Donnell" delivers the latest news and original reporting, and goes beyond the headlines with context and depth. Catch the CBS Evening News every weekday night at 6:30 p.m. ET on the CBS Television Network and at 12 a.m. ET on the CBS News app. Subscribe to the "CBS Evening News" YouTube channel: https://youtube.com/CBSEveningNews Watch full episodes of "CBS Evening News": https://cbsnews.com/evening-news/full-episodes/ Follow "CBS Evening News" on Instagram: https://instagram.com/cbseveningnews/ Like "CBS Evening News" on Facebook: https://facebook.com/CBSEveningNews Follow "CBS Evening News" on Twitter: https://twitter.com/CBSEveningNews Download the CBS News app: https://cbsn.ws/1Xb1WC8 Try Paramount+ free: https://paramountplus.com/?ftag=PPM-05-10aeh8h For video licensing inquiries, contact: [email protected]