Police say a Uniondale man has been arrested in the death of a 17-month-old boy.

Lord Pardo, 26, was arrested Monday morning and is charged with one count of second-degree murder.

Police say Pardo was at his Uniondale home Sunday baby-sitting his girlfriend's son, Mason Robinson, and his own 3-week-old daughter. They say that Pardo had been dating Robinson's mother for the last four months, and watched Robinson occasionally while she was at work.

Authorities say Pardo severely beat Robinson, fracturing his skull and ribs, as well as damaging his lungs and liver.

Officials say the child was pronounced dead Sunday afternoon at North Shore-LIJ Hospital in Syosset.

Prosecutors say Pardo claimed Robinson was injured after jumping on a bed and falling off. 

Pardo's attorney says his client has no criminal record and never would have hurt the child.

Pardo was arraigned in Hempstead court and is being held on $20 million bond or $10 million cash bail.

He's due back in court Oct. 15.