Two shootings at opposite ends of the city have one common thread: Police don't know why victims were shot

Boston Police Commissioner William Evans says police are seeking the public's help in their investigations of a double shooting in Charlestown that left one teen dead and a shooting in Dorchester Lower Mills that sent a man to the hospital with head injuries.

At a public meeting in Lower Mills to discuss that neighborhood's shooting, Evans said police still do not know exactly why the victims were shot.

He said both the teens in Charlestown - Ryan Morrissey, who died, and Jamie Lawton - were "good kids" who had never been in any trouble with the law and who weren't doing anything suspicious when shot.

Evans said that in the Lower Mills case, police know there was an argument in the parking lot of the CVS on Richmond Street right before Keldon Liverpool, a father of three, was shot. But he said investigators don't know if Liverpool was involved in that argument, or if he just happened to be in the wrong place at the wrong time.

The commissioner said detectives hope video from nearby surveillance cameras can provide some clues - or that somebody who saw or knows what happened will contact police.

In both cases, information can be forwarded anonymously to the anonymous tip line, 800-494-TIPs or by texting TIP to 27463.