A man who allegedly stabbed a Richfield couple last year, killing the man, pleaded guilty Thursday to murder and attempted murder.

Leon Henry Anderson, 24, of Minneapolis, is expected to be sentenced June 11 to about 37 years in prison, or 450 months — more than the state guideline of 340 months.

He had rejected a plea deal in September but has since agreed that three other charges, including first-degree murder, will be dropped for his guilty plea, the Hennepin County attorney’s office said Thursday.

Anderson had done odd jobs for Richard Webb, 79, and Toni Gail Jackson-Webb, 62, before stabbing them on Feb. 28, 2012, killing Webb and leaving Jackson-Webb lying injured on the floor of her house for three days before a relative stopped by and called police.

Anderson, who knew the couple and had been hired to shovel their sidewalk, stole their 2008 Cadillac, which police later found with blood on the gas pedal, in the driver’s foot well and on the driver’s door handle.

He said in court that he had become angry with Webb, hitting him in the head several times and then cutting his throat with a knife.

Anderson admitted that he then went after Webb’s wife, intending to kill her and cut her across the throat. Webb-Jackson was found injured and barely conscious but survived the attack.