(CNN)A lot of questions. Not too many answers. Exactly one week after being taken into police custody in Baltimore, Freddie Gray died Sunday under circumstances that are unclear. "The questions that many of you have are the same questions that we're asking: How was Mr. Gray injured? Were our proper protocols and procedures actually followed? What are the next steps to take from here?" said Baltimore Mayor Stephanie Rawlings-Blake. An attorney for Gray's family alleges that police are involved in a cover-up. "On last Sunday morning at about 8 a.m., the police chased Freddie Gray, a ... healthy man, without any evidence he had committed a crime. His take-down and arrest without probable cause occurred under a police video camera, which taped everything including the police dragging and throwing Freddy into a police vehicle while he screamed in pain," attorney William Murphy Jr. said in a statement. Video recorded at the scene shows Gray, with his hands behind his back, screaming as police raise him to his feet. They drag him to a waiting van. "He lapsed into a coma, died, was resuscitated, stayed in a coma and on Monday, underwent extensive surgery at Shock Trauma to save his life. He clung to life for seven days and died today at approximately 7 a.m.  We believe the police are keeping the circumstances of Freddie's death secret until they develop a version of events that will absolve them of all responsibility," said Murphy. The attorney added that Gray's spinal cord was severely injured. At this point, police are declining to say much about the case, citing ongoing administrative and criminal investigations. They have not released the incident report, nor have they released the names of the officers involved. They have said that those officers have been placed on administrative duties. When asked why officers first encountered Gray, Baltimore Police Dept. Capt. Eric Kowalczyk told CNN that they had been working in an area known for violent crime and drug sales. When the officers approached him, Gray fled, Kowalczyk said. Gray's death comes amid a string of recent deaths involving white officers and black suspects. The death of Michael Brown in Ferguson, Missouri, touched off protests and sparked a nationwide debate over race and policing. Brown, an unarmed black teen, was shot by Darren Wilson, a white officer, last August. According to CNN affiliate WJZ, protesters rallied over the weekend in Baltimore, demanding answers. "Our hope and goal here is to be as informative as we can without compromising the criminal investigation," said Kowalczyk. "We're very troubled by this. We want to find out the answers as much as the public does." CNN's Vivan Kuo and Janet DiGiacomo contributed to this report.
An attorney for Freddie Gray's family alleges that police are involved in a cover-up.
There are ongoing administrative and criminal investigations.
Baltimore's mayor promises to get the bottom of what happened.