The second defendant in a break-in turned slaying in south Minneapolis last summer pleaded guilty to second-degree intentional murder just as his trial was set to begin Wednesday.

Semaj Williams, 22, of Brooklyn Park, faced a possible life sentence for first-degree murder and first-degree burglary for the July 20, 2011, killing of Shea Stremcha, 25. In exchange for his plea, Williams will serve a 38-year prison sentence. He is scheduled for sentencing March 26.

Stremcha was asleep at 3 a.m. with his fiancée in their home in the 2900 block of 45th Avenue S. in the Longfellow neighborhood when she heard glass break. She woke Stremcha, who grabbed a knife and went to confront the burglars. He was shot once in the heart. A 2008 graduate of St. John's University, Stremcha worked at Ameriprise Financial in Minneapolis.

Williams, Robert Emmanuel Shelby, 28, and Xavier Demia Walker, 25, were charged in the case. Shelby, of St. Paul, pleaded guilty to second-degree murder last April in exchange for a 35-year sentence. Walker is scheduled to stand trial on first-degree murder charges March 4.

According to the Hennepin County attorney's office, Williams admitted in court that he, Shelby and Walker planned a break-in and robbery that night at the nearby home of a drug dealer near Lake Street and 45th Avenue S. to steal money and drugs. He said they broke into the wrong house and when Stremcha came around the corner, Walker shot him.