By Tony Hanson

PHILADELPHIA (CBS) — A Philadelphia man has pleaded guilty to killing a 20-month-old toddler by rubbing drain cleaner on the child’s body.

Aaron Pace, 36, today pleaded guilty to third-degree murder for killing Sulaiman Orrell-Kirkland in 2010.

It was a painful, torturous death over five days: the boy had burns over about 20 percent of his body.  According to investigators, Pace committed the atrocious act because the boy was fussing and crying during bathtime.

(Sulaiman Orrell-Kirkland, in family photo)

Pace was a family friend, described in court as “like family,”  who has admitted he got mad and grabbed a container of drain-cleaning crystals and rubbed them over the boy’s body with a rag.

The result has left even veteran first-responders affected to this day, and the family is of course devastated.

The defendant, described by his defense attorney as “low functioning” with a low IQ, said he was sorry and was taking responsibility for his actions.

Pace has been sentenced to 17½ to 35 years in prison.