A South Salt Lake man was arrested Monday night in connection with the death of a 2-year-old boy who was killed Sunday.

The toddler's mother put her son down for a nap about 10:30 a.m. Sunday and then left him in the care of her live-in boyfriend while she went to church. When she returned home about 1 p.m., her boyfriend was asleep and her son was asleep in his crib, a police report stated.Jennifer Watts, 20, stuck her head into the room of her home at 270 E. 1750 South but didn't notice anything wrong until she decided to wake the baby about 5:15 p.m. At that point, she noticed that her child, Paul Eugene Watts, 2, was dead.

Autopsy results showed that the boy had received several "striking blows" and had died as a result of multiple head injuries, said Salt Lake Police Lt. Jim Bell. "It doesn't take much for a baby," he said.

A friend of the family told police that the mother was apprehensive about leaving the baby with the man because they had found bruises on him a week earlier and could not explain them. Police said the baby had received some bruising on his buttocks.

The boyfriend told the woman he had been asleep while she was at church, the report said.

Michael Douglas Lane, 28, 270 Wilson Ave., was arrested and booked into the Salt Lake County Jail for investigation of criminal homicide, jail records state. Detectives said they plan to meet with the Salt Lake County attorney's office to discuss the case.

Sunday's homicide was the second child killed in Salt Lake County in the past two weeks. An 11-month-old child, Jay Thompson, son of George and Kay Thompson of West Valley City, died Jan. 29 after he was apparently shaken to death. A Kearns woman who was baby-sitting the child has been charged with second-degree murder in connection with the death.

Police say Lane had been living at the Salt Lake address for about two months.