> reporter: prosecutors knew when cara rintala was arrested in late 2011 for murder, they had a mighty challenge on their hands. and so it proved. the trial opened in early 2013. and it ended, three weeks later, with a hung jury. >> breaking news, a northampton jury has failed to come to a unanimous verdict. >> reporter: a year later, in 2014, trial number two. same thing happened, incredible as it seems. another hung jury. Get Live News Updates Every Minute from vimarsana.com Curated from 23000 News Agencies.">
> reporter: prosecutors knew when cara rintala was arrested in late 2011 for murder, they had a mighty challenge on their hands. and so it proved. the trial opened in early 2013. and it ended, three weeks later, with a hung jury. >> breaking news, a northampton jury has failed to come to a unanimous verdict. >> reporter: a year later, in 2014, trial number two. same thing happened, incredible as it seems. another hung jury. Get Live News Updates Every Minute from vimarsana.com Curated from 23000 News Agencies." property="og:description">
> reporter: prosecutors knew when cara rintala was arrested in late 2011 for murder, they had a mighty challenge on their hands. and so it proved. the trial opened in early 2013. and it ended, three weeks later, with a hung jury. >> breaking news, a northampton jury has failed to come to a unanimous verdict. >> reporter: a year later, in 2014, trial number two. same thing happened, incredible as it seems. another hung jury. Get Live News Updates Every Minute from vimarsana.com Curated from 23000 News Agencies.">
now back to "dateline. ". welcome back to "dateline." i'm craig melvin. as prosecutors ready for trial, they had little physical evidence to support their case. could they convince a jury that this doting mother was also a killer. here again is dennis murphy with "at the bottom of the stairs." >> reporter: prosecutors knew when cara rintala was arrested in late 2011 for murder, they had a mighty challenge on their hands. and so it proved. the trial opened in early 2013. and it ended, three weeks later, with a hung jury. >> breaking news, a northampton jury has failed to come to a unanimous verdict. >> reporter: a year later, in 2014, trial number two. same thing happened, incredible as it seems. another hung jury.