article_snippet.sent: But it's unclear how Gray, who was arrested on a weapons charge April 12, suffered a severe spinal cord injury that led to his death seven days later.
article_snippet.sent: What we know: Freddie Gray was arrested on a weapons charge in a high-crime area of Baltimore known for drugs.
article_snippet.sent: What we don't know: It's unknown what caused the spinal cord injury that led to Freddie Gray death a week after the arrest, and it's also unknown what, if anything, happened inside a police van.
article_snippet.sent: What we know: According to court documents CNN obtained, there were more than 20 criminal court cases in Maryland against Freddie Gray, and five of more than 20 criminal court cases in Maryland against Gray were still active at the time of Freddie Gray death.
article_snippet.sent: more than 20 criminal court cases in Maryland against Gray involve mostly drug-related charges, but there are charges from March for second-degree assault and destruction of property.
article_snippet.sent: Freddie Gray was due in court on a possession charge on April 24.
article_snippet.sent: Freddie Gray had been in and out of prison since 2009 for various drug cases, according to Maryland Department of Corrections spokesman Gerard Shields.
article_snippet.sent: In February 2009, Freddie Gray was sentenced to four years in prison for two counts of drug possession with intent to deliver.
article_snippet.sent: Freddie Gray was paroled on June 30, 2011.
article_snippet.sent: On April 4, 2012, Freddie Gray was arrested for violating parole but Maryland Department of Corrections spokesman Gerard Shields didn't go back to prison, Maryland Department of Corrections spokesman Gerard Shields said, reasoning that  whatever Freddie Gray allegedly did, it "was something minor."
article_snippet.sent: Freddie Gray did return to prison in May 2013 for drug possession, serving a month behind bars before Freddie Gray release in June.
article_snippet.sent: What we don't know: It's not known whether Freddie Gray's criminal past had anything to do with Freddie Gray arrest, or Freddie Gray death.
highlights_snippet.sent: Freddie Gray was arrested on a weapons charge April 12; Freddie Gray was dead seven days later .
  
highlights_snippet.sent: Freddie Gray has a criminal history but Freddie Gray's not known if that had anything to do with Freddie Gray arrest or death .